Table grapes are food products of considerable commercial value for several countries (USA, Brazil, Italy, South Africa, China, Chile, India and Australia are the most important producers). In Europe, Italy ranks first place for table grape production with more than eight million tons per year (ISTAT, 2011). Recently, we developed an innovative analytical method for the characterization of various table grape cultivars. In our study, multivariate statistical analysis applied to 1H NMR data of table grapes, revealed that the inter-vineyard variability of the metabolic profile has a greater discriminating effect over the intra-vineyard one.1 This presentation deals with the effects of several agronomical practices on the metabolic profile of the table grapes during different production stages. The variation of the metabolic features of the grapes was followed by 1H NMR spectroscopy. Moreover, 1H NMR spectra of ripe table grapes were processed to be used as input for expert classification systems based on three different algorithms: J48, Random Forest and an Artificial Neural Network performed with the Error Back Propagation procedure. The performances of the three algorithms in the discrimination of grapes on the bases of some common features (variety, vintage, use of plant growth regulators, trunk girdling, vineyard location) will be shown. References: 1. V. Gallo, P. Mastrorilli, I. Cafagna, G. I. Nitti, M. Latronico, V. A. Romito, A. P. Minoja, C. Napoli, F. Longobardi, H. Schäfer, B. Schütz, M. Spraul, J. Agric. Food Chem. (2012), submitted.

Table grapes classification is an important task in the global market because of the interest of consumers to quality of foodstuff. Objective: an expert and innovative tool, based on several robust classifiers, was designed and implemented to achieve unequivocal criteria and support decision for the discrimination of table grapes. Materials: data are acquired by powerful analytical techniques such as Nuclear Magnetic Resonance (NMR) and are related to 5 attributes: production year, vineyard location, variety, use of plant growth regulators (PGRs) and application of trunk girdling. In particular, datasets consisting of 813 samples regarded the former 3 attributes while datasets based on 596 samples regarded the latter 2 ones. Methods: in absence of an a-priori knowledge, we addressed the problem as an inferential task and then adopted supervised approaches like error back propagation neural networks, trees and random forest classifiers able to manage information from training sets. Experimental Results and Conclusion: our study has shown that the three classifiers, especially that based on a supervised neural network, when applied to NMR data, give from good to excellent performances, depending on the attribute. Such performances pave the way to development of innovative tools for classification of table grapes.

This work describes the one-pot direct reductive amination of carbonyl compounds with nitroarenes promoted by a polymer supported palladium catalyst, in the presence of molecular hydrogen as the reductant. This methodology is applicable, with slight differences, to both aliphatic and aromatic aldehydes. The operational simplicity, the mild reaction conditions, the high yields and the good recyclability of the supported catalyst are major advantages of this method. TEM observations of the catalyst showed that the active species are palladium nanoparticles having a size distribution centered at 5 nm within the polymeric support. (C) 2011 Elsevier B.V. All rights reserved.

An oxidative coupling of amines to give imines in ionic liquids (ILs) under metal-free aerobic conditions has been developed. The high efficiency achievable in ILs is mechanistically explained in terms of activation of the starting materials (benzylamine and molecular oxygen) by an initial electron transfer, promoted by the ionic nature of the solvent. Reactivity data of variously p-substituted benzylamines show a general deactivating effect, which would imply a change in the rate-determining step in the reaction mechanism.

This work deals with the catalytic conversion of benzyl alcohols to aldehydes or ketones using a polymer supported palladium catalyst which formed metal nanoparticles under reaction condition. The oxidation reaction was carried out on a series of substituted benzylic alcohols under air in water. The obtained results showed high selectivity also for the oxidation of primary alcohols to aldehydes without over-oxidation products. In addition, the catalyst was recycled several times with negligible metal leaching into solution.

Palladium nanoparticles supported on chitosan (Pd-NPs@Chitosan) have been used for the first time in Suzuki cross coupling of bromo and iodoarenes carried out in ionic liquids. The reaction proceeded smoothly in molten tetrabutylammonium bromide (TBAB) affording unsymmetrical biaryls in good to excellent yields. A low catalyst loading (0.1%) is used and the catalyst can be recycled without deactivation.

This chapter contains sections titled: Procedure Discussion Waste Disposal Information Appendix: Experimental Supplement Notes References

Suzuki couplings of aryl bromides were efficiently performed by a polymer supported palladium catalyst under air in water at 100 ◦C without additives. In the case of activated aryl chlorides the reactions proceeded smoothly in the presence of a suitable phase transfer agent. The catalyst was active and recyclable for at least five times. Atomic absorption analyses revealed that the metal content in the polymeric support did not significantly decrease with the cycles while inductively coupled plasma analyses revealed that the palladium amount both in the mother liquors and in the organic products after reactions was lower than 500 ppb. The activity of the mother liquors has been investigated in detail. A transmission electron microscopy study of the supported catalyst before, during and after duty is also described.

Polymer supported palladium nanoparticles, generated in situ by Pd(II) reduction under reaction conditions, catalyzed the hydrogenation of nitroarenes to anilines with high efficiency in water at room temperature in the presence of NaBH4. The protocol proved to be highly selective and generally favored the formation of the desired aniline as single product in high yields with short reaction times. TEM analyses revealed that the size distribution of the formed Pd nanocrystals was regulated by the reductant agent. In details, when 1 atm H2 was used as the nitroarene reductant, the in situ generated polymer supported palladium nanoparticles were crystallites with diameters ranging from 6 to 10 nm. On the contrary, when the reaction was carried out in the presence of NaBH4 in water under N2 or air, the formation of Pd nanocrystallites was observed as well, but this time they were smaller (mean size diameter ca. 3 nm) and catalytically more active compared to the palladium nanoparticles formed under 1 atm H2 in the absence of NaBH4. The catalyst displayed excellent recyclability over twelve cycles and no leaching of metal into solution occurred, which made the overall system eco-friendly and economic.

X-ray powder diffraction was combined, for the first time, with Nuclear Magnetic Resonance spectroscopy and direct infusion mass spectrometry to characterise fresh and brined grape leaves. Covariance analysis of data generated by the three techniques was performed with the aim to correlate information deriving from the solid part with those obtained for soluble metabolites. The results obtained indicate that crystalline components can be correlated to the metabolites contained in the grape leaves, paving the way to the use of X-ray diffraction analysis for food fingerprinting purposes. Moreover it was ascertained that, differently from most of the metabolites present in the fresh vine leaves, linolenic acid (an omega-3-fatty acid) and quercetin-3-O-glucuronide (a polyphenol metabolite) do not undergo sensible degradation during the brining process, which is used as preservative method for the grape leaves. (C) 2013 Elsevier Ltd. All rights reserved.

The reactivity of the complexes [PtCl2{Ph2PN(R)PPh2-P,P}] (R = −H, 3; R = −(CH2)9CH3, 8) toward group 6 carbonylmetalates Na[MCp(CO)3] (M = W or Mo, Cp = cyclopentadienyl) was explored. When R = H, the triangular clusters [PtM2Cp2(CO)5(μ-dppa)] (M = W, 4; M = Mo, 5), in which the diphosphane ligand bridges a Pt-M bond, were obtained as the only products. When R = −(CH2)9CH3, isomeric mixtures of the triangular clusters [PtM2Cp2(CO)5{Ph2PN(R)PPh2-P,P}], in which the diphosphane ligand chelates the Pt center (M = W, 11; M = Mo, 13) or bridges a Pt–M bond (M = W, 12; M = Mo, 14), were obtained. Irrespective of the M/Pt ratio used when R = −(CH2)9CH3, the reaction of [PtCl2{Ph2PN(R)PPh2-P,P}] with Na[MCp(CO)3] in acetonitrile stopped at the monosubstitution stage with the formation of [PtCl{MCp(CO)3}{Ph2PN(R)PPh2-P,P}] (R = −(CH2)9CH3, M = W, 9; M = Mo, 10), which are the precursors to the trinuclear clusters formed in THF when excess carbonylmetalate was used. The dynamic behavior of the dppa derivatives 4 and 5 in solution as well as that of their carbonylation products 6 and 7, respectively, is discussed. Density functional calculations were performed to study the thermodynamics of formation of 4 and 5 and 11–14, to evaluate the relative stabilities of the chelated and bridged forms and to trace a possible pathway for the formation of the trinuclear clusters.

We have recently described the synthesis of the complex [(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2(PHCy2)] (Pt-Pt) (1), the first unsymmetrical phosphinito bridged Pt(I) species.[1] The phosphinito bridge differentiates the charge distributions on the two platinum atoms as confirmed by NMR spectroscopy (dPt(1) = -4798 ppm, dPt(2) = -5207 ppm) and DFT studies. Complex 1 shows a rich chemistry as it reacts with nucleophiles [PHCy2, PCy3, P(S)HCy2],[2] protic species HX [P(OH)Cy2, PhSH, HF, HCl, HBr, HI, HBF4],[3, 4] and small molecules such as H2.[5] Recently, we started investigations on the reactivity of complex 1 towards Au and Ag based electrophiles. In this communication, it will be shown that, differently from the isolobal H+ (which attacks the phosphinito oxygen and migrates onto the Pt-Pt bond),3 the [Ag(PPh3)]+ electrophile attacks complex 1 selectively to the Pt2-mP bond to afford the cationic cluster [(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2{m- -Ag(PPh3)}(PHCy2)]+ (Pt–Pt) (2+) in which the [Ag(PPh3)]+ moiety bridges the mP-Pt2 bond. Analogous reactivity is observed also when phosphane free electrophiles such as AgOTf, AgBF4, AgClO4 and AgCl are used. Moreover, the reactivity of 1 towards Au(I) electrophiles such as AuCl and [Au(PPh3)Cl] was dependent on the reagent and on the experimental conditions. references: 1. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.; Suranna, G. P.; Ciccarella, G.; Englert, U.; Eur. J. Inorg. Chem., 2005, 4607–4616. 2. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.; Polini, F.; Re, N.; Englert, U.; Inorg. Chem., 2008, 47, 4785–4795. 3. Latronico, M.; Polini, F.; Gallo, V.; Mastrorilli, P; Calmuschi-Cula B.; Englert, U.; Re, N.; Repo T., Raisanen M.; Inorg. Chem., 2008, 47, 9979-9796. 4. M. Latronico, P. Mastrorilli, V. Gallo, M.M.Dell’Anna, F. Creati, N. Re, U. Englert, Inorg. Chem. 2011, 50, 3539–3558 5. Mastrorilli P., Latronico M., Gallo V., Polini F., Re N., Marrone A., Gobetto R., Ellena S.. J. Am. Chem. Soc. 2010, 132, 4752–4765

The reactivity of the phosphinito bridged Pt(I) complex [(PHCy2)Pt1(μ-PCy2){κ2P,O-μ- P(O)Cy2}Pt2(PHCy2)](Pt–Pt) (1) towards Au(I) and Ag(I) electrophiles was explored. Treatment of 1 with AuCl yielded the dichloro Pt(II) complex [(Cl)(PHCy2)Pt (μ-PCy2){κ210 P,O-μ-P(O)Cy2)Pt (Cl)(PHCy2)] (4), while [Au(PPh3)Cl] in thf (or toluene) caused ligand exchange resulting in the formation of [(PPh3)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(PHCy2)](Pt–Pt) (7) and [(PPh3)Pt(μ-PCy2){κ2P,O- μ-P(O)Cy2}Pt(PPh3)](Pt–Pt) (8). With [Au(PPh3)OTf] (independently from the solvent) or with [Au(PPh3)Cl] (only in dichloromethane), reaction with 1 gave [(PHCy2)Pt1(μ-PCy2){κ2P,O-μ- P(O)Cy2}Pt215 {μ-Au(PPh3)}(PHCy2)]X(Pt–Pt) ([6]X, X = OTf, Cl) clusters in which the [Au(PPh3)] moiety bridges the μP-Pt2 bond. The [Ag(PPh3)]+ electrophile attacks complex 1 selectively at the Pt2-μP bond to afford, at low T, the cationic cluster [(PHCy2)Pt1(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt2{μ- Ag(PPh3)}(PHCy2)]+(Pt–Pt) (10+) in which the [Ag(PPh3)]+ moiety bridges the μP-Pt2 bond. Clusters analogous to 10+, but without PPh3 bonded to Ag, are obtained from reactions of 1 with AgOTf, AgBF4, AgClO4 and AgCl.

Nutritional features of table grapes are the result of a complex combination of human practices with weather and environmental conditions. In the present study, the influence of agronomical practices on the chemical composition of commercial table grapes was studied by simple and fast Nuclear Magnetic Resonance (NMR)-based methods. In particular, variability of grape composition was evaluated considering primary metabolites, the compounds directly involved in growth and development of fruits and reliably detected by NMR spectroscopy. Three case studies of increasing complexity were examined. Primarily, it was found that inter-vineyard composition variability has a greater discriminating effect than intra-vineyard variability. The quantities of glucose, fructose, arginine and ethanol are the most dependent on farming practices. The comparison between organic and conventional productions (cv. Superior Seedless) showed a higher sugar content for the conventional practices, resulting in a higher sugar-to-acid ratio. For cultivars Red Globe and Italia, the factors most affected by farming practices were the glucose-to-fructose ratio and the amounts of arginine and ethanol.

The rational synthesis of dinuclear asymmetric phosphanido derivatives of palladium and platinum(II), [NBu4][(R-F)(2)M(mu-PPh2)(2)M'(kappa(2),N,C-C13H8N)] (R-F = C6F5; M = M' = Pt, 1; M = Pt, M' = Pd, 2; M = Pd, M' = Pt, 3; M = M' = Pd, 4), is described. Addition of I-2 to 1-4 gives complexes [(R-F)(2)M-II(mu-PPh2)(mu-I)Pd-II{PPh2(C13H8N)}] (M = M' = Pt, 6; M = Pt, M' = Pd, 7; M = M' = Pd, 8; M = Pd, M' = Pt 10) which contain the aminophosphane PPh2(C13H8N) ligand formed through a Ph2P/(CN)-N-boolean AND reductive coupling on the mixed valence M(II)-M'(IV) [NBu4][(R-F)(2)M-II(mu-PPh2)(2)M'(IV)(kappa(2),N,C- C13H8N)I-2] complexes, which were identified for M-II = Pd, M'(IV) = Pt (9), and isolated for M-II = Pt, M'(IV) = Pt (5). Complex 5 showed an unusual dynamic behavior consisting in the exchange of two phenyl groups bonded to different P atoms, as well as a "through space" spin-spin coupling between ortho-F atoms of the pentafluorophenyl rings.

The complex trans-[PtCl(PCy2)(PHCy2)2] (1) possesses a terminal phosphanido group (PCy2) and a chloride ligand, which render it a good candidate for the synthesis of phosphanido- bridged heterodimetallic species (PHCy2)2Pt(μ- PCy2)M–L by reaction either with carbonyl metalates, as metal-based nucleophiles, or with metal-based electrophiles. The heterodinuclear complexes [(PHCy2)2Pt(μ-PCy2)Co- (CO)3](Pt–Co) (2), [(PHCy2)2Pt(μ-PCy2)Mo(CO)2Cp](Pt–Mo) (3), and [(PHCy2)2Pt(μ-PCy2)W(CO)2Cp](Pt–W) (4) are obtained by reaction of 1 with the carbonyl metalates Na[Co- (CO)4], Na[Mo(CO)3Cp] and Na[W(CO)3Cp], respectively. Although 2 is reluctant to react with carbon monoxide, 3 and 4 are promptly carbonylated under ambient conditions to afford mixtures of the cis and trans isomers of [(PHCy2)(CO)- Pt(μ-PCy2)M(CO)2Cp] (M = Mo or W), which interconvert through dissociation/reassociation of the CO ligand coordinated to the Pt centre. The reaction of 1 with AuCl(PPh3) leads to the formation of the trinuclear Pt2Au complexes cisand trans-[{Cl(PHCy2)2Pt(μ-PCy2)}2Au]Cl (cis- and trans- [8]Cl), in which a Au atom bridges two molecules of 1 through the originally terminal phosphanide ligands.

The reactivity of the dinuclear platinum(III) derivative [(RF)2PtIII(μ-PPh2)2PtIII(RF)2](Pt−Pt) (RF = C6F5) (1) toward OH−, N3 −, and NCO− was studied. The coordination of these nucleophiles to a metal center evolves with reductive coupling or reductive elimination between a bridging diphenylphosphanido group and OH−, N3 −, and NCO− or C6F5 groups and formation of P−O, P−N, or P−C bonds. The addition of OH− to 1 evolves with a reductive coupling with the incoming ligand, formation of a P−O bond, and the synthesis of [NBu4]2[(RF)2PtII(μ-OPPh2)(μ-PPh2)- PtII(RF)2] (3). The addition of N3 − takes place through two ways: (a) formation of the P−N bond and reductive elimination of PPh2N3 yielding [NBu4]2[(RF)2PtII(μ-N3)(μ-PPh2)PtII(RF)2] (4a) and (b) formation of the P−C bond and reductive coupling with one of the C6F5 groups yielding [NBu4][(RF)2PtII(μ-N3)(μ- PPh2)PtII(RF)(PPh2RF)] (4b). Analogous behavior was shown in the addition of NCO− to 1 which afforded [NBu4]2[(RF)2PtII(μ-NCO)(μ-PPh2)PtII(RF)2] (5a) and [NBu4][(RF)2PtII(μ-NCO)(μ-PPh2)PtII(RF)(PPh2RF)] (5b). In the reaction of the trinuclear complex [(RF)2PtIII(μ-PPh2)2PtIII(μ-PPh2)2PtII(RF)2](PtIII−PtIII) (2) with OH− or N3 −, the coordination of the nucleophile takes place selectively at the central platinum(III) center, and the PPh2/OH− or PPh2/N3 − reductive coupling yields the trinuclear [NBu4]2[(RF)2PtII(μ-Ph2PO)(μ-PPh2)PtII(μ-PPh2)2PtII(RF)2] (6) and [NBu4]- [(RF)2Pt1(μ3-Ph2PNPPh2)(μ-PPh2)Pt2(μ-PPh2)Pt3(RF)2](Pt2−Pt3) (7). Complex 7 is fluxional in solution, and an equilibrium consisting of Pt−Pt bond migration was ascertained by 31P EXSY experiments.

In this study, non-targeted (1)H NMR fingerprinting was used in combination with multivariate statistical techniques for the classification of Italian sweet cherries based on their different geographical origins (Emilia Romagna and Puglia). As classification techniques, Soft Independent Modelling of Class Analogy (SIMCA), Partial Least Squares Discriminant Analysis (PLS-DA), and Linear Discriminant Analysis (LDA) were carried out and the results were compared. For LDA, before performing a refined selection of the number/combination of variables, two different strategies for a preliminary reduction of the variable number were tested. The best average recognition and CV prediction abilities (both 100.0%) were obtained for all the LDA models, although PLS-DA also showed remarkable performances (94.6%). All the statistical models were validated by observing the prediction abilities with respect to an external set of cherry samples. The best result (94.9%) was obtained with LDA by performing a best subset selection procedure on a set of 30 principal components previously selected by a stepwise decorrelation. The metabolites that mostly contributed to the classification performances of such LDA model, were found to be malate, glucose, fructose, glutamine and succinate.

The dynamic behavior in solution of eight mono-hapto tetraphosphorus transition metal-complexes, trans-[Ru(dppm)2(H)(η1-P4)]BF4 ([1]BF4), trans-[Ru(dppe)2(H)(η1-P4)]BF4 ([2]BF4), [CpRu(PPh3)2(η1-P4)]PF6 ([3]PF6), [CpOs(PPh3)2(η1-P4)]PF6 ([4]PF6), [Cp*Ru(PPh3)2(η1-P4)]PF6 ([5]PF6), [Cp*Ru(dppe)(η1-P4)]PF6 ([6]PF6), [Cp*Fe(dppe)(η1-P4)]PF6 ([7]PF6), [(triphos)Re(CO)2(η1-P4)]OTf ([8]OTf), and of three bimetallic Ru(μ,η1:2-P4)Pt species [{Ru(dppm)2(H)}(μ,η1:2-P4){Pt(PPh3)2}]BF4 ([1-Pt]BF4), [{Ru(dppe)2(H)}(μ,η1:2-P4){Pt(PPh3)2}]BF4 ([2-Pt]BF4), [{CpRu(PPh3)2)}(μ,η1:2-P4){Pt(PPh3)2}]BF4 ([3-Pt]BF4), [dppm=bis(diphenylphosphanyl)methane; dppe=1,2-bis(diphenylphosphanyl)ethane; triphos=1,1,1-tris(diphenylphosphanylmethyl)ethane; Cp=η5-C5H5; Cp*=η5-C5Me5] was studied by variable-temperature (VT) NMR and 31P{1H} exchange spectroscopy (EXSY). For most of the mononuclear species, NMR spectroscopy allowed to ascertain that the metal-coordinated P4 molecule experiences a dynamic process consisting, apart from the free rotation about the MP4 axis, in a tumbling movement of the P4 cage while remaining chemically coordinated to the central metal. EXSY and VT 31P NMR experiments showed that also the binuclear complex cations [1-Pt]+–[3-Pt]+ are subjected to molecular motions featured by the shift of each metal from one P to an adjacent one of the P4 moiety. The relative mobility of the metal fragments (Ru vs. Pt) was found to depend on the co-ligands of the binuclear complexes. For complexes [2]BF4 and [3]PF6, MAS, 31P NMR experiments revealed that the dynamic processes observed in solution (i.e., rotation and tumbling) may take place also in the solid state. The activation parameters for the dynamic processes of complexes 1+, 2+, 3+, 4+, 6+, 8+ in solution, as well as the X-ray structures of 2+, 3+, 5+, 6+ are also reported. The data collected suggest that metal-coordinated P4 should not be considered as a static ligand in solution and in the solid state.

Among the various vineyard treatments adopted in recent years for table-grape cultivation, there has been a significant use of plant growth regulators (PGRs) and girdling to increase berry size and yield. In particular, an increase in the application of forchlorfenuron (CPPU) and gibberellic acid (GA3) for many seeded and seedless table-grape cultivars has been registered in several countries. In this two-year study, girdling at berry set, gibberellic acid (10 mg/L) applied at berry diameter of 10 to 11 mm, and forchlorfenuron (9.75 mg/L) applied at berry diameter of 11 to 12 mm were investigated to verify their effects on berry size, yield, and chemical and metabolic characteristics of Italia grapes. In general, at harvest all treatments significantly increased berry diameter, length, and weight and consequent cluster weight and yield/vine compared to an untreated control. The treatments showed significant differences for the colorimetric parameters, in particular a higher value of hue for berries treated with GA3 and CPPU, thus shifting the skin color from yellow toward yellow-green. Metabolomic study carried out by nuclear magnetic resonance spectroscopy combined with principal component analysis indicated that metabolic profile depends on the year and, in each year, the effect of treatments consisted of a slight variation of amino acid content. Treatments effects were more pronounced in the year characterized by a cooler summer.

The reaction of the neutral binuclear complexes [(R(F))(2)Pt(mu-PPh(2))(2)M(Phen)1 (phen = 1,10-phenanthroline, R(F) = C(6)F(5); M = Pt, 1; M = Pd, 2) with AgClO(4) or [Ag(OClO(3))(PPh(3))] affords the trinuclear complexes [AgPt(2)(mu-PPh(2))(2)(R(F))(2)(Phen)(OClO(3))] (7a) or [AgPtM(mu-PPh(2))(2)(RF)(2)(Phen)(PPh(3))] [ClO(4)] (M = Pt, 8; M = Pd, 9), which display an "open-book" type structure and two (7a) or one (8,9) Pt Ag bonds. The neutral diphosphine complexes [(R(F))(2)Pr(mu-PPh(2))(2)m(P P)] (P P = 1,2-bis(diphenylphosphino)methane, dppm, M = Pt, 3; M = Pd, 4; P P = 1,2-bis(diphenylphosphino)ethane, dppe, M = Pt, 5; M = Pd, 6) react with AgClO(4) or [Ag(OClO(3))(PPh(3))], and the nature of the resulting complexes is dependent on both M and the diphosphine. The dppm Pt Pt complex 3 reacts with [Ag(OClO(3))(PPh(3))], affording a silver adduct 10 in which the Ag atom interacts with the Pt atoms, while the dppm Pt Pd complex 4 reacts with [Ag(OClO(3))(PPh(3))], forming a 1:1 mixture of [AgPdPt(mu-PPh(2))(2)(RF)(2)(OClO(3))(dppm)] (11), in which the silver atom is connected to the Pt-Pd moiety through Pd (mu-PPh(2)) Ag and Ag-P(k'-dppm) interactions, and [AgPdPt(mu-PPh(2))(2) (R(F))(2)(OClO(3))(PPh(3))(2)] [ClO(4)] (12). The reaction of complex 4 with AgClO(4) gives the trinuclear derivative 11 as the only product. Complex 11 shows a dynamic process in solution in which the silver atom interacts alternatively with both Pd-mu PPh(2) bonds. When P-P is dppe, both complexes 5 and 6 react with AgClO(4) or [Ag(OClO(3))(PPh(3))], forming the saturated complexes (M = Pt, 13; Pd, 14), which are the result of an oxidation followed by a PPh(2)/C(6)F(5) reductive coupling. Finally, the oxidation of trinuclear derivatives [(R(F))(2)Pt(II)(mu-PPh(2))(2)Pt(II)(mu-4PPh(2))(2)Pt(II)L(2)] (L(2) = phen, 15; L = PPh(3), 16) by AgClO(4) results in the formation of the unsaturated 46 VEC complexes [(R(F))(2)Pt(III)(mu-PPh(2))(2)Pt(III)(mu-PPh(2))(2)Pt(II)L(2)][ClO(4)](2) (17 and 18, respectively) which display Pt(III)-Pt(III) bonds.

Neutral, end-on bound white-phosphorus complexes with unprecedented stability in the solid state and solution were synthesized (see structure: gray C, blue Mn, red O, violet P). While the C5(4-nBuC6H4)5 ligands are stationary at low temperature on the NMR timescale, the P4 ligands rotate rapidly. Despite the unfavorable γP/γH ratio, a heteronuclear Overhauser effect between the protons in ortho position and the basal P atoms was detected.

The reactions of [Ag(OClO3)(PPh3)] with [NBu4][(C6F5)2Pt(μ- PPh2)2M(hq)], [NBu4][(C6F5)2Pt(μ-PPh2)2M(bq)], [NBu4]- [(C6F5)2Pt(μ-PPh2)2M(pic)] and [NBu4][(C6F5)2Pt(μ-PPh2)2Pt- (C6F5)(tht)] (M = Pt, Pd; hq = 8-hydroxyquinolinate, bq = benzoquinolinate, pic = picolinate, tht = tetrahydrothiophene) afford the corresponding neutral adducts [(C6F5)2Pt- (μ-PPh2)2(μ-AgPPh3)M(bq)] (M = Pt, 1; Pd, 2), [(C6F5)2Pt(μ- PPh2)2(μ-AgPPh3)M(hq)] (M = Pt, 3; Pd, 4) [(C6F5)2Pt(μ-PPh2)2- (μ-AgPPh3)Pt(C6F5)(tht)] (5) and [(C6F5)2Pt(μ-PPh2)2M(pic- AgPPh3)] (M = Pt, 6; Pd, 7) as yellow solids. The XRD structures of 1–5, in which a [AgPPh3]+ moiety bridges the metal centres, were confirmed in solution at low temperature. At room temperature, a dynamic process for the [AgPPh3]+ moiety, which passes from the top to the bottom part of the molecules 1–5, was ascertained. For 6 and 7, the XRD analyses revealed structures in which the [AgPPh3]+ moiety is linked to the picolinate oxygen atom bonded to the M centre; however, although such a structure was confirmed in solution for the Pt–Pd species 7, the stable form of the Pt–Pt species 6 in solution is that with the [AgPPh3]+ moiety bridging the metal centres.

The dinuclear anionic complexes [NBu4][(R-F)(2)M-II(mu-PPh2)(2)M'(II)((NO)-O-boolean AND)](R-F = C6F5. (NO)-O-boolean AND = 8-hydroxyquinolinate, hq; M = M' = Pt 1; Pd 2; M = Pt, M' = Pd, 3. (NO)-O-boolean AND = o-picolinate, pic; M = Pt, M' = Pt, 4; Pd, 5) are synthesized from the tetranuclear [NBu4](2)[{(R-F)(2)Pt(mu-PPh2)(2)M(mu-Cl)}(2)] by the elimination of the bridging Cl as AgCl in acetone, and coordination of the corresponding N,O-donor ligand (1, 4, and 5) or connecting the fragments "cis-[(R-F)(2)M(mu-PPh2)(2)](2-)" and "M'((NO)-O-boolean AND)" (2 and 3). The electrochemical oxidation of the anionic complexes 1-5 occurring under HRMS(+) conditions gave the cations [(R-F)(2)M(mu-PPh2)(2)M'((NO)-O-boolean AND)](+), presumably endowed with a M(III),M'(III) core. The oxidative addition of I-2 to the 8-hydroxyquinolinate complexes 1-3 triggers a reductive coupling between a PPh2 bridging ligand and the N,O-donor chelate ligand with formation of a P-O bond and ends up in complexes of platinum(II) or palladium(II) of formula [(R-F)(2)M-II(mu-I)(mu-PPh2)M'(II)(P,N-PPh(2)hq)], M = M' = Pt 7, Pd 8; M = Pt, M' = Pd, 9. Complexes 7-9 show a new Ph2P-OC9H6N (Ph2P-hq) ligand bonded to the metal center in a P,N-chelate mode. Analogously, the addition of I-2 to solutions of the o-picolinate complexes 4 and 5 causes the reductive coupling between a PPh2 bridging ligand and the starting N,O-donor chelate ligand with formation of a P-O bond, forming Ph2P-OC6H4NO (Ph2P-pic). In these cases, the isolated derivatives [NBu4][(Ph2P-pic)(R-F)Pt-II(mu-I)(mu-PPh2)M-II(R-F)I] (M = Pt 10, Pd 11) are anionic, as a consequence of the coordination of the resulting new phosphane ligand (Ph2P-pic) as monodentate P-donor, and a terminal iodo group to the M atom. The oxidative addition of I-2 to [NBu4][(R-F)(2)Pt-II(mu-PPh2)(2)Pt-II(acac)] (6) (acac = acetylacetonate) also results in a reductive coupling between the diphenylphosphanido and the acetylacetonate ligand with formation of a P-O bond and synthesis of the complex [NBu4][(R-F)(2)Pt-II(mu-I)(mu-PPh2)Pt-II(Ph2P-acac)I] (12). The transformations of the starting complexes into the products containing the P-O holds passes through mixed valence M(II),M'(IV) intermediates which were detected, for M = M' = Pt, by spectroscopic and spectrometric measurements.

The UVB-induced photocatalytic degradation of Methyl Red and Methyl Orange (azo dyes used in the textile industry) containing solutions was carried out by the use of a laboratory-scale pilot plant where the catalyst, TiO2 (anatase), was immobilized at the bottom of a channel through which the liquid was recirculated under UVB irradiation. The plant was preliminarily characterized hydrodynamically, i.e., flow-rate, hydraulic gradients, and residence time. Photodegradation kinetics were followed by UV−vis absorption measurements of the residual dye concentration in the liquid-phase, and the synergistic effects of the catalyst and radiation in promoting the abatement of dyes was demonstrated in the concentration range 0.3−5.0 mg/L. Kinetic data were correlated by the use of first-order (or pseudo-first-order) models up to the concentration range 0.7 mg/ L; at higher concentrations, zero-order models (pure catalytic control) better correlated the experimental data. Photocatalytic degradation of Methyl Red was faster than Methyl Orange, possibly due to the Coulomb repulsion of the negatively charged sulfonate functionalities present on this latter compound. A better hydrodynamic of the liquid recirculating in the channel, i.e., higher flow rate (lower contact time), associated with an improved surface catalyst renovation and a higher frequency of exposition of the substrate to the UVB radiation, together with an improved oxygen dissolution in the liquid-phase, played a positive role in the overall kinetic performance.

An innovative laboratory scale unit was used to carry out UV photoinduced catalytic degradation of methyl 9 orange. For this purpose, the experimental system was made of a bottom and an upper reservoir (∼120 L each) which were connected by an inclined channel through which water was recirculated. TiO2 (Anatase) was deposited (∼10−2 mg/cm2) at the bottom of the connecting channel while the Methyl Orange solution was exposed to the UVB radiation (λ ≈ 300 nm) during its recirculation through the connecting channel. The unit was first characterized from both the hydrodynamic and the hydraulic points of view. Photodegradation kinetics were followed by UV−vis absorption measurements of the residual methyl orange solution concentration along time, and the synergic effect of the catalyst and the intensity of the UV radiation in promoting degradation of the substrate was demonstrated. The abatement efficiency of the UV/TiO2 system toward methyl orange was evaluated in the concentration range 0.3−8.5 mg/L. Kinetic patterns were described by first (or pseudofirst) order theoretical models up to the concentration of 0.7 mg/L, whereas at higher concentrations kinetic trends were better described by zero-order models independently from the substrate concentration in the liquid-phase. The proposed solution, after an upscale field investigation, may represent a valuable alternative to the methods conventionally used for the abatement of textile dyes from wastewater, that is, water clarification, reverse osmosis, activated carbon sorption, and biosorption.

This work demonstrates how the directing ability of the azetidine ring could be useful for regioselective ortho-C-H functionalization of aryl compounds. Robust polar organometallic (lithiated) intermediates are involved in this synthetic strategy. The reagent n-hexyllithium emerged as a safer, yet still effective, basic reagent for the hydrogen/lithium permutation relative to the widely used reagent nBuLi. Two different reaction protocols were discovered for regioselective lithiation at the ortho positions adjacent to the azetidine ring, which served as a toolbox when other competing directing groups were installed on the aromatic ring. The coordinating ability of the azetidine nitrogen atom, as well as the involvement of dynamic phenomena related to the preferential conformations of 2-arylazetidine derivatives, were recognized to be responsible for the observed reactivity and regioselectivity. A site-selective functionalization of the aromatic ring was achieved for aryl azetidines with either coordinatively competent groups (e.g. methoxy) or inductively electron-withdrawing substituents (e.g. chlorine and fluorine). By fine-tuning the reaction conditions, regioselective introduction of several substituents on the aromatic ring could be realized. Several substitution patterns were accomplished, which included 1,2,3-trisubstitution, 1,2,3,4-tetrasubstitution, and 1,2,3,4,5-pentasubstitution, up to the exhaustive substitution of the aromatic ring.

The manuscript describes the design, preparation and characterization of two structurally isomeric random poly(arylene−vinylene)s, the properties of which have been optimized for their use as donor materials in BHJ solar cells. The structure of the polymers was aimed at broadening as much as possible their absorption profile. Poly[9,9-dioctylfluorene− vinylene-co-4,7-dithiophen-2-yl-benzo[1,2,5]thiadiazole−vinylene] (P1) and poly[2,7-dithiophen-2-yl-9,9-dioctylfluorene−vinylene- co-4,7-benzo[1,2,5]thiadiazole−vinylene] (P2) were prepared using the Suzuki−Heck polymerization. The polymers were characterized by elemental analysis, NMR, UV−vis absorption and photoluminescence, cyclic voltammetry, and GPC. The electrochemical characterization of P1 and P2 revealed similar HOMO/LUMO energy levels, although the UV−vis absorption profile of P2 is markedly broader than the one exhibited by P1. The more panchromatic absorption of P2 was explained by DFT and TDDFT calculations showing that the model systems, contributing together to the description of the random polymeric structure, exhibited different calculated excitation energies, that cover a broader portion of the absorption spectrum. In BHJ solar cells, the broadness of the absorption strongly influences the BHJ solar cell performances of P2 compared to P1 leading to higher short circuit currents and to a 3-fold higher power conversion efficiency. The PCE value (0.6%) obtained with P2 is in line with those obtained for other poly(heteroarylene−vinylene)s donors and is amenable to improvement by optimizing the device construction (PC61BM amount in the blend or use of annealing processes). These results demonstrate how combination of a suitable choice of the sequence of aryl units together with the potentialities offered by random polymers, can be useful tools in the design of new light-harvesting polymers in BHJ.

Extensive intramolecular π-conjugation is considered to be requisite in the design of organic semiconductors. Here, two inkjet pigments, epindolidione and quinacridone, that break this design rule are explored. These molecules afford intermolecular π-stacking reinforced by hydrogen-bonding bridges. Air-stable organic field effect transistors are reported that support mobilities up to 1.5 cm2/Vs with T80 lifetimes comparable with the most stable reported organic semiconducting materials.

The initiation of the Suzuki cross-coupling polymerisation with a fluorene-based AB-type monomer was finely tuned within the chain-growth regime by the suitable control of the species generated by the Pd(AcO)2/t-Bu3P/K3PO4 catalytic system. The prototypical poly(9,9-di-n-octyl-fluorene) was obtained with extremely fast (1 min) polymerisation rates, excellent polydispersities (1.16) and molecular weights dependent on the monomer/catalyst molar ratio, without the need to resort to formal chain-initiators.

OFETs based on new solution-processed ester functionalized 9,10-ter-anthrylene-ethynylenes show a mobility increase of four orders of magnitude, leading to mobilities as high as 4.9 × 10-2 cm 2 V-1 s-1 if the deposited film is annealed before contact deposition. The behavior is ascribed to an increase in film order at the dielectric/semiconductor interface as revealed by X-ray studies.

The manuscript deals with the synthesis and properties of four new all-donor alternating poly(arylene-ethynylene)s DBSA, DBSTA, DTSA, and DTSTA. The polymers have been obtained by a Sonogashira cross-coupling of 9,10-diethynyl-anthracene with the dibromo-derivatives of 9,9-dioctyldibenzosilole (DBSA), 2,7-dithienyl-9,9-dioctyl-dibenzosilole (DBSTA), 4,4-dioctyl-dithienosilole (DTSA), or 2,6-dithienyl-9,9dioctyl-dithienosilole (DTSTA). The polymers exhibited absorption profiles and frontier orbital energies strongly dependent on their primary structure. Density functional theory calculations confirmed experimental observations and provided an insight into the electronic structure of the macromolecules. In particular, the effects exerted by the thiophene units in DBSTA and DTSTA on the optical properties of the corresponding INTRODUCTION The p-conjugated polymers have widely been employed as light-harvesting electron donor materials in bulk heterojunction (BHJ) solar cells, since they can be suitably designed to provide the necessary light harvesting as well as a favorable mixing with fullerene-based electron acceptors. 1 An ideal donor material for BHJ solar cells should possess the following requisites: (i) a broad absorption spectrum in the range of wavelengths where the solar photon flux is maximum (i.e., 500–800 nm); (ii) a thermodynamically feasible electron transfer to the acceptor materials (usually fullerene derivatives); (iii) an efficient hole transport; (iv) a relatively deep highest occupied molecular orbital (HOMO) energy. All these properties independently influence polymers could be rationalized with respect to DBSA and DTSA. Preliminary photovoltaic measurements have established that the performance of DTSA is among the highest reported for an all-donor polymer. Moreover, UV irradiation of DTSA films under air evidenced a remarkable photostability of this material, providing further evidence that ethynylenecontaining electron-rich systems are promising donors for organic solar cells applications.

This study deals with the synthesis and characterization of two new di-anchoring dyes for applications in dye-sensitized solar cells. The materials were designed with a branched D(-π-A)2 structure containing (i) a rigid alkyl-functionalized carbazole core as the donor part, (ii) one (DYE1) or two (DYE2) thiophene units as the π-bridge and (iii) a cyano-acrylic moiety as acceptor and anchoring part. Electrochemical impedance spectroscopy indicated that the injected electron lifetime is higher in the case of DYE2, probably due to the length of the π-spacer that, in combination with the alkyl chain on the carbazole unit, hampers the charge recombination with the electrolyte. Stability tests on TiO2-sensitized films revealed that the di-anchoring remarkably slows down the desorption process, which conversely is evident for classic reference dyes. The highest power conversion efficiency reaches 5.01% in the case of DYE2 with a photovoltage of 0.70 V and a photocurrent of 10.52 mA cm−2, substantially deriving from a broader absorption with respect to DYE1, as also confirmed by IPCE measurements. These results support the efforts aimed at the structural engineering of D(-π-A)2 dyes to design new, more efficient and stable organic sensitizers.

This study deals with an investigation of the spectral stability of differently structured polyfluorenes (PFs), deprived of 9-H defects, embodying 9,9-dialkylfluorene (P1), 9,9-diarylfluorene (P2), or 9,9-diarylfluorene/9,9- dibenzylfluorene units in a 1:1 alternating fashion (P3). Thermal annealing or UV irradiation carried out on films of P1-P3 in air revealed that their typical blue photoluminescence is invariably stained, independently of their 9-substitution, by the appearance of the low-energy band (g-band) pointing out a remarkable effect of light on the degradation process. A more comprehensive picture of the degradation pathway is proposed, including as key step a light-promoted formation of a PF radical cation generated by aerobic oxidation (photoluminescence test) or p-doping (cyclic voltammetry test). The blue emission of P1-P3 could successfully be preserved by dispersing them into a higher band gap matrix, such as polyvinylcarbazole (PVK), indicating a fundamental role of the intermolecular interactions between PF chains in the appearance of the low-energy emission band. Comparison between the optical behavior of suitably prepared PFs containing either fluorenone moieties (PFK) or 9-(bis-methylsulfanyl-methylene)fluorene moieties (PFS) holds regions of planarity within the PF backbone (inducing local intermolecular interactions) and not the fluorenone charge-transfer emission as responsible of the g-band of degraded PFs.