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NMR spectroscopy has recently been utilized to determine the absolute amounts of organic molecules with metrological traceability since signal intensity is directly proportional to the number of each nucleus in a molecule. The NMR methodology that uses hydrogen nucleus (1H) to quantify chemicals is called quantitative 1H-NMR (1H qNMR). The quantitative method using 1H qNMR for determining the purity or content of chemicals has been adopted into some compendial guidelines and official standards. However, there are still few reports in the literature regarding validation of 1H qNMR methodology. Here, we coordinated an international collaborative study to validate a 1H qNMR based on the use of an internal calibration methodology. Thirteen laboratories participated in this study, and the purities of three samples were individually measured using 1H qNMR method. The three samples were all certified via conventional primary methods of measurement, such as butyl p-hydroxybenzoate Japanese Pharmacopeia (JP) reference standard certified by mass balance; benzoic acid certified reference material (CRM) certified by coulometric titration; fludioxonil CRM certified by a combination of freezing point depression method and 1H qNMR. For each sample, 1H qNMR experiments were optimized before quantitative analysis. The results showed that the measured values of each sample were equivalent to the corresponding reference labeled value. Furthermore, assessment of these 1H qNMR data using the normalized error, En-value, concluded that statistically 1H qNMR has the competence to obtain the same quantification performance and accuracy as the conventional primary methods of measurement.

Two-dimensional urea- and thiourea-containing covalent organic frameworks (COFs) were synthesized at ambient conditions at large scale within 1 h in the absence of an acid catalyst. The site-isolated urea and thiourea in the COF showed enhanced catalytic efficiency as a hydrogen-bond-donating organocatalyst compared to the molecular counterparts in epoxide ring-opening reaction, aldehyde acetalization, and Friedel-Crafts reaction. The COF catalysts also had excellent recyclability.

The coordination of the S-based anions, thiophenoxide (PhS, a), ethyl xanthogenate (EtOCS, b), 2-mercaptopyridinate (pyS, c), and 2-mercaptopyrimidinate (pymS, d), to the central platinum atom of the trinuclear Pt(III),Pt(II) complex [(CF)Pt(μ-PPh)Pt(μ-PPh)Pt(CF)](Pt-Pt), 1, gives rise to three different types of complexes: (i) the Pt(II),Pt(II),Pt(II) complex [NBu][(CF)Pt(μ-PPh)Pt{κ-S,P-μ-(PhS)PPh}(μ-PPh)Pt(CF)], 2a; (ii) the Pt(II),Pt(IV),Pt(II) mixed valence complexes [NBu][(CF)Pt(μ-PPh)Pt(κ-S,S′-EtOCS)(μ-PPh)Pt(CF)], 3b, and [NBu][(CF)Pt(μ-PPh)Pt{κN,P-(pymS)PPh}(μ-PPh)Pt(CF)], 3d; and (iii) the Pt(II),Pt(II),Pt(II) derivatives [NBu][(CF)Pt(μ-PPh)Pt{κN,P-μ-(pyS)PPh}(μ-PPh)Pt(CF)], 4c, and [NBu][(CF)Pt(μ-PPh)Pt{κN,P-μ-(pymS)PPh}(μ-PPh)Pt(CF)], 4d. Complexes 2a, 4c, and 4d display new PhP(SL) ligands stemming from the reductive coupling of a PPh group and the S-based anions. Complex 2a exhibits a κ-S,P bridging coordination mode while 4c and 4d exhibit a κ-N,P mode in the solid state. In acetone solution, an equilibrium between the κ-N,P and the κ-S,P forms was ascertained for complexes with 2-mercaptopyrimidinate and 2-mercaptopyridinate by NMR techniques. Complex 4d evolved, in acetone solution at 323 K, to the Pt(II),Pt(II),Pt(II) complex [NBu][(CF)Pt(μ-PPh){κ-P,N-μ-(Pym)PPh}Pt(κ-S,P-μ-SPPh)(μ-PPh)Pt(CF)], 5d. The X-ray diffraction structures of the trinuclear complexes 3′b (the complex having the same anion as 3b but PhP=N=PPh as the countercation instead of NBu) and 4d are described., Dedicated to Prof. Pablo Espinet on the occasion of his 70th birthday. This work was supported by the Spanish MINECO/FEDER (Proyect CTQ2015-67461-P) and the Gobierno de Aragón and Fondo Social Europeo (Grupo de Referencia E17_17R: Química Inorgánica y de los Compuestos Organometálicos).

In order to investigate photophysical properties and crystallization medium effects, three Cu complexes, [CuI(PCy3)]2 (1), [Cu(I)(PPh2Me)]4 (2), and [Cu4(I)4(PPh2py)2] (3) were prepared and characterized using single crystal X-ray crystallography, solid state NMR, UV–Vis, and IR spectroscopy. In 1, as previously reported, Cu2I2 core is a square dimer with alternating copper and iodides positioned in the corners. Each copper atom is surrounded by two bridging iodides and a terminal tricyclohexylphosphine ligand. The cluster 2 adopts a cubane-like Cu4I4 core, while in cluster 3 (as thf solvate) a Cu4I2 distorted octahedral core is decorated with two bridging iodides and two chelating P^N ligands. The solid state 31P NMR analysis showed the presence in the powder of several polymorphs, the most abundant of which being, in the case of 2, the cubane-like structure resolved by XRD methods, and in the case of 3, a butterfly structure, different from that found for 3·thf. The solid state blue photoluminescence intensity in 1 is dependent upon its poly- or single-crystallinity. While dimer 1 in polycrystalline form is a stronger blue light emitter under 254 nm light irradiation than in 365 nm, in single crystalline phase it shows a similar higher intensity blue luminescence under lower energy light (365 nm) irradiation. On the other hand, clusters 2 and 3 do not show phase-dependent luminescence intensity variation. Time-dependent Density Functional Theory (TD-DFT) showed that the emission in 1 and 3 is assigned to a mixed metal to ligand and halide to ligand charge transfer, (X + M)LCT. In 2, a dual emission band at low temperature was observed which was attributed to 3CC (LE band) and 3XLCT (HE band). Thermochromism and mechanochromism of complexes 1–3 were also investigated.

Four Schiff base manganese(III) complexes with derivatives of [(R,R)-N,N’-bis(salicy1idene)-1,2-cyclohexanediaminato)] including substituents on salicylaldehyde such as 3-methoxy, 3,5-di-tert-butyl and 3,5-chloro were synthesized and characterized using a combination of IR, UV–Vis, and HR ESI-MS techniques. The catalytic activity of these complexes was tested in the oxidation of 1-phenylethanol to acetophenone, revealing very good performances for all of the four manganese complexes. The catalytic reactions were carried out in the presence of tert-butyl hydroperoxide (TBHP) as oxidant and imidazole as co-catalyst. Complex Mn-4, bearing electron withdrawing [(R,R)-N,N’-bis(3,5-di-chloro-salicylidene)-1,2-cyclohexanediaminato)] ligand was found to be the most stable of the tested Mn(III) complexes and was selected for the oxidation of several primary and secondary alcohols.

A new covalent organic framework (COF) based on imine bonds was assembled from 2-(4-formylphenyl)-5-formylpyridine and 1,3,6,8-tetrakis(4-aminophenyl)pyrene, which showed an interesting dual-pore structure with high crystallinity. Postmetallation of the COF with Pt occurred selectively at the N donor (imine and pyridyl) in the larger pores. The metallated COF served as an excellent recyclable heterogeneous photocatalyst for decarboxylative difluoroalkylation and oxidative cyclization reactions.

NMR spectroscopy has recently been utilized to determine the absolute amounts of organic molecules with metrological traceability since signal intensity is directly proportional to the number of each nucleus in a molecule. The NMR methodology that uses hydrogen nucleus (

The reaction of the dinuclear phosphinito bridged complex [(PHCy2)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(PHCy2)](Pt-Pt) (1) with phenylacetylene affords the η1-alkenyl-μ,η1:η2-alkynyl complex [(η1-trans-(Ph)HC[double bond, length as m-dash]CH)(PHCy2)Pt(μ-PCy2)(μ,η1:η2-PhC[triple bond, length as m-dash]C)Pt{κP-P(O)Cy2}(PHCy2)] (4) displaying a σ-bonded 2-phenylethenyl ligand and an alkynyl (μ-κCα:η2) bridge between the platinum atoms. Complex 4 was shown to form in two steps: initially, the attack of the first molecule of phenylacetylene gives the σ-acetylide complex [(PHCy2)(η1-PhC[triple bond, length as m-dash]C)Pt1(μ-PCy2)Pt2(PHCy2){κP-P(OH)Cy2}](Pt-Pt) (5) featuring an intramolecular π-type hydrogen bond between the POH and the C[triple bond, length as m-dash]C triple bond; fast reaction of 5 with a second molecule of phenylacetylene results in the oxidative addition of the terminal C-H bond of the second alkyne to Pt1 that, after rearrangements, leads to 4. When left in solution for two weeks, complex 4 spontaneously isomerizes completely to [(PHCy2)(η1-trans-(Ph)HC[double bond, length as m-dash]CH)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(η1-PhC[triple bond, length as m-dash]C)(PHCy2)] (7) displaying a 2-phenylethenyl ligand and a phenylethynyl group both σ-bonded to the metal. Density functional calculations at the B3LYP/LACV3P++**//DFT/LACVP* level were carried out to study the thermodynamics of the formation of all considered complexes and to trace the mechanism of formation of the observed products.

This work was supported by the Spanish Ministerio de Economía y Competitivad/FEDER (Proyect PGC2018-094749-B-I00) and by the Gobierno de Aragón (Grupo E17_17R: Química Inorgánica y de los Compuestos Organometálicos). Politecnico di Bari is gratefully acknowledged for financial support (FRA funds to M. L. and P. M.).

The first adducts of NHCs (=N‐heterocyclic carbenes) with aromatic polyphosphorus complexes are reported. The reactions of [Cp*Fe(η5‐P5)] (1) (Cp*=pentamethyl‐cyclopentadienyl) with IMe (=1,3,4,5‐tetramethylimidazolin‐2‐ylidene), IMes (=1,3‐bis(2,4,6‐trimethylphenyl)‐imidazolin‐2‐ylidene) and IDipp (=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene) led to the corresponding neutral adducts which can be isolated in the solid state. However, in solution, they quickly undergo a dissociative equilibrium between the adduct and 1 including the corresponding NHC. The equilibrium is influenced by the bulkiness of the NHC. [Cp′′Ta(CO)2(η4‐P4)] (Cp′′=1,3‐di‐tert‐butylcyclopentadienyl) reacts with IMe under P atom abstraction to give an unprecedented cyclo‐P3‐containing anionic tantalum complex. DFT calculations shed light onto the energetics of the reaction pathways., Access to polyphosphorus complexes: A dynamic behavior between [Cp*Fe(η5‐P5)] and NHCs in solution is reported. NMR investigations showed a bond formation and bond breaking process between [Cp*Fe(η5‐P5)] and the NHCs. Despite this dynamic behavior in solution, adducts of [Cp*Fe(η5‐P5)] and NHCs can be isolated as solids. The tantalum complex [Cp′′Ta(CO)2(η4‐P4)] reacts with the NHC via a phosphorus atom abstraction and a ring contraction to a novel anionic cyclo‐P3 complex.

The synthesis and characterization of three six-coordinated Pt(IV) complexes with the stoichiometry [Pt(Ar)2(S∧N)2] (S∧N = Sbt, benzothiazole-2-thiolate, Ar = p-MeC6H4 (1a), C6F5 (1b); S∧N = Spy, 2-pyridinethiolate, Ar = p-MeC6H4 (1c)) is described. Of these, 1a undergoes, at room temperature and within 18 h, a remarkable C–C reductive elimination process between the aryl ligands to give, as the final products, the stable binuclear lantern complex [Pt2(Sbt)4] (2a) and 4,4′-dimethylbiphenyl. Differently from 1a, solutions of 1b,c are indefinetively stable up to 60 °C and do not undergo reductive elimination. Complexes 1a–c and 2a were characterized by IR and NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray crystallography (1b,c and 2a). 1H–19F HOESY experiments on 1b demonstrated the presence of a “through-space” coupling between proximal F and H atoms of the molecule that are separated by six bonds but are in close spatial proximity.

The reaction of the dinuclear phosphinito bridged complex [(PHCy2)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(PHCy2)](Pt–Pt) (1) with phenylacetylene affords the η1-alkenyl-μ,η1:η2-alkynyl complex [(η1-trans-(Ph)HCCH)(PHCy2)Pt(μ-PCy2)(μ,η1:η2-PhCC)Pt{κP-P(O)Cy2}(PHCy2)] (4) displaying a σ-bonded 2-phenylethenyl ligand and an alkynyl (μ-κCα:η2) bridge between the platinum atoms. Complex 4 was shown to form in two steps: initially, the attack of the first molecule of phenylacetylene gives the σ-acetylide complex [(PHCy2)(η1-PhCC)Pt1(μ-PCy2)Pt2(PHCy2){κP-P(OH)Cy2}](Pt–Pt) (5) featuring an intramolecular π-type hydrogen bond between the POH and the CC triple bond; fast reaction of 5 with a second molecule of phenylacetylene results in the oxidative addition of the terminal C–H bond of the second alkyne to Pt1 that, after rearrangements, leads to 4. When left in solution for two weeks, complex 4 spontaneously isomerizes completely to [(PHCy2)(η1-trans-(Ph)HCCH)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(η1-PhCC)(PHCy2)] (7) displaying a 2-phenylethenyl ligand and a phenylethynyl group both σ-bonded to the metal. Density functional calculations at the B3LYP/LACV3P++**//DFT/LACVP* level were carried out to study the thermodynamics of the formation of all considered complexes and to trace the mechanism of formation of the observed products.

Nuclear Magnetic Resonance (NMR) is an analytical technique extensively used in almost every chemical laboratory for structural identification. This technique provides statistically equivalent signals in spite of using spectrometer with different hardware features and is successfully used for the traceability and quantification of analytes in food samples. Nevertheless, to date only a few internationally agreed guidelines have been reported on the use of NMR for quantitative analysis. The main goal of the present study is to provide a methodological pipeline to assess the reproducibility of NMR data produced for a given matrix by spectrometers from different manufacturers, with different magnetic field strengths, age and hardware configurations. The results have been analyzed through a sequence of chemometric tests to generate a community-built calibration system which was used to verify the performance of the spectrometers and the reproducibility of the predicted sample concentrations.

Non-targeted NMR-based approach has received great attention as a rapid method for food product authenticity assessment. The availability of a database containing many comparable NMR spectra produced by different spectrometers is crucial to develop functional classifiers able to discriminate rapidly the commodity class of a given food product. Nevertheless, variability in spectrometer features may hamper the production of comparable spectra due to inherent variations in signal resolution. In this paper, we report on the development of a class-discrimination model for grape juice authentication by application of non-targeted NMR spectroscopy. Different approaches for the pre-treatment of data will be described along with details about the model validation. The developed model performed excellently (95.4-100% correct predictions) even when it was tested against 650 spectra produced by 65 spectrometers with different configurations (magnetic field strength, manufacturer, age). This study may boost the use of non-targeted NMR methods for food control.

Spectroscopic non-targeted methods are gaining ever-growing importance in quality control and authenticity assessment of food products because of their strong potential for identification of specific features of the products by data-driven classifiers. One of the factors hampering the diffusion of spectroscopic non-targeted methods and data-driven classifiers is the lack of harmonized guidelines for their development and validation. In particular, to date, neither conditions to directly compare spectra recorded by different spectrometers nor studies demonstrating the statistical equivalence of the spectra are available. Among the spectroscopic analytical techniques suitable for the development of non-targeted methods, nuclear magnetic resonance (NMR) offers the unique opportunity to generate statistically equivalent signals. In this paper, the feasibility of NMR spectroscopy to generate statistically equivalent NMR signals from a number of different spectrometers was demonstrated for complex mixtures (aqueous extracts of wheat and flour) by organizing an inter-laboratory comparison involving 36 NMR spectrometers. Univariate statistics along with multivariate analysis were exploited to establish unbiased criteria for assessing the statistical equivalence of the NMR signals. The aspects affecting the signal equivalence were investigated, and possible solutions to reduce the extent of the human error were proposed and applied with satisfactory results. This study furnishes the scientific community with an appropriate and easy procedure to validate non-targeted NMR methods and provides error values to be used as a reference for future studies.

A mixture of the asymmetric complexes of formula [(R)Pt(μ-PhPO)(μ-PPh)Pt(μ-PPh)Pt(solv)(solv′)] [(1-(solv)(solv′)] (solv, solv′ = acetone, HO, CHCN) has been prepared by reaction of [(R)Pt(μ-PPh)Pt(μ-PPh)Pt(NCCH)] with AgClO in CHCN/acetone. The lability of the Pt-solvent bonds allows the displacement of the coordinated solvent molecules by dppm or Cl and the isolation of the tri- or hexanuclear phosphanido/phosphinito Pt(ii) complexes [(CF)Pt(μ-PPh)(μ-PPhO)Pt(μ-PPh)Pt(dppm)] (2) or [NBu][(CF)Pt(μ-PPh)(μ-PPhO)Pt(μ-PPh)Pt(μ-Cl)Pt(μ-PPh)Pt(μ-PPh)(μ-PPhO)Pt(CF)] (as a mixture of the two possible isomers 4a and 4b). Complex 2 reacts with AgClO to form the tetranuclear derivative [(CF)Pt(μ-PPh)(μ-PPhO)Pt(μ-PPh)Pt(dppm)Ag(OClO)] (3), which displays two Pt-Ag donor-acceptor bonds. The mixture of the hexanuclear isomers 4a-4b reacts with Tl(acac) producing the acetylacetonato complex [NBu][(CF)Pt(μ-PPh)(μ-PPhO)Pt(μ-PPh)Pt(acac)] (5) which, upon reaction with HCl, yields back the mixture of 4a-4b. The reaction of 4a-4b with PPh produces [NBu][(CF)Pt(μ-PPh)(μ-PPhO)Pt(μ-PPh)Pt(Cl)(PPh)] (6) as a mixture of isomers with the chloro ligand located syn (6a) or anti (6b) to the PPhO group. Either the reaction of 6 with AgClO or the treatment of 5 with HPPhClO results in the formation of the species [(CF)Pt(μ-PPh)Pt(μ-PPhOPPh)Pt(PPh)] (7) (44 VEC), which can be explained as the consequence of a PPhO/PPh reductive coupling and a rearrangement of ligands in the molecule generating a Pt(ii),Pt(i),Pt(i) compound. All complexes were characterised in the solid state by XRD (only one of the isomers, in the cases of 4 and 6) and in solution by NMR spectroscopy., This work was supported by Ministerio de Economía y Competitividad (MINECO)/FEDER (project number CTQ2012-35251) and the Gobierno de Aragón and Fondo Social Europeo (Grupo Consolidado E21: Química Inorgánica y de los Compuestos Organometálicos). We express our grateful acknowledgement to the Politecnico di Bari for its financial support.

Lipids of sewage scum and primary sludge taken from several wastewater treatment plants were quantified and characterised. In sewage scum, lipids represented 36–50% of total solids and were primarily composed of free fatty acids (45–60%) and calcium soaps (27–35%). In primary sludge, total lipids were 20–24% of total solids, and 71–82% of these were calcium soaps. Estolides and 10-hydroxystearic acid (prevalently present as R enantiomer, with an enantiomeric excess >92%) were also identified and quantified. A scheme of valorisation was then specifically designed and positively tested for both the sludge. Lipids were first recovered (92–99%), activated and finally reacted with methanol and AlCl3∙6H2O (343 K, 2 h, yield >96%). Besides biodiesel, methyl estolides and methyl 10-hydroxystearate were efficiently isolated and purely separated in different fractions. A preliminary feasibility study was finally conducted and a possible integration of processes into a wastewater treatment plant was proposed and positively evaluated.

31P and 195Pt solid state NMR spectra of anti-[(PHCy)ClPt(μ-PCy2)2Pt(PHCy)Cl] (3) and [(PHCy2)Pt(μ-PCy2)(κ2P,O-μ-POCy2)Pt(PHCy2)] (Pt-Pt) (4) were recorded under cross polarization/magic-angle spinning conditions (31P) or with the cross polarization/Carr-Purcell-Meiboom-Gill pulse sequence (195Pt) and compared to the data obtained by relativistic DFT calculations of 31P and 195Pt CS tensors and isotropic shielding at the ZORA spin-orbit level. A good agreement with the experimental results was found and it was possible to rationalize the chemical shift differences of 195Pt and 31P nuclei between compounds 3 and 4 as mostly due to a change (in opposite directions for 195Pt and 31P) of the principal component of the shielding tensor perpendicular to the molecular plane defined by the Pt and P atoms. Paramagnetic and spin-orbit terms were found to be the most important contributions to 195Pt and 31P shielding.

Reaction of [Pt(κ2-C,N-ppy)(dmso)Cl], 1 (Hppy = 2-phenylpyridine), with Na[H2B(mb)2] (Hmb = 2-mercapto-benzimidazole) smoothly afforded the complex {[(κ3-S,B,S-HB(mb)2]Pt(κ2-C,N-ppy)H}, 2, featuring a strong reverse-dative Pt → B σ interaction in the solid state. When dissolved in thf (or acetone) solution, 2 undergoes a reversible Pt–H bond activation, establishing an equilibrium between the hexacoordinated 2 and the tetracoordinate complex {[(κ2-S,S-H2B(mb)2]Pt(κ2-C,N-ppy)}, 3, as ascertained by multinuclear NMR. Hydrolysis of the B–N bond in 2/3 resulted ultimately in the formation of a dimeric half-lantern platinum(II,II) complex [{Pt(κ2-C,N-ppy)(μ2-κ2-N,S-mb)}2], 4. The SC-XRD structures of 2 and 4 are reported.

Multinuclear (31P, 195Pt, 19F) solid-state NMR experiments on (nBu4N)2[(C6F5)2Pt(μ-PPh2)2Pt(C6F5)2] (1), [(C6F5)2Pt(μ-PPh2)2Pt(C6F5)2](Pt–Pt) (2), and cis-Pt(C6F5)2(PHPh2)2 (3) were carried out under cross-polarization/magic-angle-spinning conditions or with the cross-polarization/Carr–Purcell Meiboom–Gill pulse sequence. Analysis of the principal components of the 31P and 195Pt chemical shift (CS) tensors of 1 and 2 reveals that the variations observed comparing the isotropic chemical shifts of 1 and 2, commonly referred to as “ring effect”, are mainly due to changes in the principal components oriented along the direction perpendicular to the Pt2P2 plane. DFT calculations of 31P and 195Pt CS tensors confirmed the tensor orientation proposed from experimental data and symmetry arguments and revealed that the different values of the isotropic shieldings stem from differences in the paramagnetic and spin–orbit contributions., The Politecnico di Bari, the University of Padua, the University of Stuttgart, the Spanish MINECO/FEDER (Project No. CTQ2012-35251), and the Gobierno de Aragon (Grupo Consolidado E21: Quimica Inorganica y de los Compuestos Organometalicos) are gratefully acknowledged for financial support.

The reactivity of dichloroplatinum(II) complexes containing thioether-functionalized bis(diphenylphosphanyl)amines of formula (Ph2P)2N(CH2)2SR (R = (CH2)5CH3, CH2Ph) toward group 6 carbonylmetalates Na[M(CO)3Cp] (M = Mo or W, Cp = cyclopentadienyl) was explored. Reactions with two or more equivalents of Na[M(CO)3Cp] (M = Mo or W) afforded the trinuclear complexes of general formula [PtPh{M(CO)3Cp}{?-P(Ph)N(CH2CH2SR)(PPh2)-?3P,P,S}M(CO)2Cp] (3 M = Mo, R = (CH2)5CH3; 4 M = Mo, R = CH2Ph; 9 M = W, R = (CH2)5CH3; 10 M = W, R = CH2Ph), the structure of which consists of a six-membered platinacycle condensed with a four-membered M-P-N-P cycle, together with small amounts of isomeric PtM2 clusters [PtM2(CO)5Cp2{(Ph2P)2N(CH2CH2SR)-?2P,P}] (5 M = Mo, R = (CH2)5CH3; 6 M = Mo, R = CH2Ph; 11 M = W, R = (CH2)5CH3; 12 M = W, R = CH2Ph) in which the ligand (Ph2P)2NR solely chelates the Pt atom or bridges an M-Pt bond as in [PtM2(CO)5Cp2{?-(Ph2P)2N(CH2CH2SR)-?2P,P}] (7 M = Mo, R = (CH2)5CH3; 8 M = Mo, R = CH2Ph; 13 M = W, R = (CH2)5CH3; 14 M = W, R = CH2Ph). The synthesis of the trinuclear complexes 3, 4, 9, and 10 entails an unexpected P-phenyl bond cleavage reaction and phenyl migration onto Pt. When only 1 equiv of Na[M(CO)3Cp] (M = Mo or W) was used, the heterodinuclear products of monosubstitution [PtCl{M(CO)3Cp}{Ph2PN(R)PPh2-P,P}] (15 M = Mo, R = (CH2)5CH3; 16 M = Mo, R = CH2Ph; 17 M = W, R = (CH2)5CH3; 18 M = W, R = CH2Ph) were obtained, which are the precursors to the bicyclic products 3, 4, 9, and 10, respectively. Density functional calculations were performed to study the thermodynamics of the formation of all the new complexes, to evaluate the relative stabilities of the isomeric chelated and bridged forms, and to trace the mechanism of formation of the phosphanido-bridged products 3, 4, 9, and 10. It was concluded that Pt(II) complexes containing a thioether-functionalized short-bite ligand, [PtCl2{Ph2PN(R)PPh2}], react with Na[M(CO)3Cp] to yield first heterodinuclear Pt-M and then heterotrinuclear PtM2 complexes resulting from the activation of a P-C bond in one of the PPh2 groups and phenyl migration to Pt. The critical role of an intramolecular thioether group was demonstrated. (Chemical Equation Presented).

Two Co(I) hydrides containing the tripodal polyphosphine ligand EP

The design of hybrid organic/inorganic nanostructures with controlled assembly drives the development of materials with new or improved properties and superior performances. In this paper, the surface and internal structure of hybrid ZnO poly-N-vinylpyrrolidone (ZnO/PVP) mesocrystals are investigated in detail and correlated with their emitting properties. A photoluminescence study at room temperature reveals that the as-synthesized particles show a remarkable ultraviolet (UV) emission, whereas an emission from defects in the visible region is not observed. On the other hand, a visible emission is achieved upon calcination of the hybrid ZnO/PVP particles in air, and its intensity is found to increase with the calcination temperature and, in some cases, to overwhelm the UV emission. A molecular description is proposed for the absence of a visible emission from defects in the as-synthesized ZnO/PVP mesocrystals on the basis of Fourier transform infrared (FTIR) and solid-state 13C NMR (SSNMR) spectroscopy. An in-depth electron microscopy study sheds light on the internal organization of mesocrystals and reveals the formation of nanoreactors, that is, particles with enclosed porosity, upon thermal treatment.

Two Co(I) hydrides containing the tripodal polyphosphine ligand EP3, (k4-EP3)Co(H) [E(CH2CH2PPh2)3; E = N (1), P (2)], have been exploited as ammonia borane (NH3BH3, AB) dehydrogenation catalysts in THF solution at T = 55 °C. The reaction has been analyzed experimentally through multinuclear (11B, 31P{1H}, 1H) NMR and IR spectroscopy, kinetic rate measurements, and kinetic isotope effect (KIE) determination with deuterated AB isotopologues. Both complexes are active in AB dehydrogenation, albeit with different rates and efficiency. While 1 releases 2 equiv of H2 per equivalent of AB in ca. 48 h, with concomitant borazine formation as the final "spent fuel", 2 produces 1 equiv of H2 only per equivalent of AB in the same reaction time, along with long-chain poly(aminoboranes) as insoluble byproducts. A DFT modeling of the first AB dehydrogenation step has been performed, at the M06//6-311++G* level of theory. The combination of the kinetic and computational data reveals that a simultaneous B-H/N-H activation occurs in the presence of 1, after a preliminary AB coordination to the metal center. In 2, no substrate coordination takes place, and the process is better defined as a sequential BH3/NH3 insertion process on the initially formed [Co]-NH2BH3 amidoborane complex. Finally, the reaction of 1 and 2 with NH-acids [AB and Me2NHBH3 (DMAB)] has been followed via VT-FTIR spectroscopy (in the -80 to +50 °C temperature range), with the aim of gaining a deeper experimental understanding of the dihydrogen bonding interactions that are at the origin of the observed H2 evolution.

Dedicated to Prof. Juan Fornies, on the occasion of his 70th birthday., The outcome of the reaction of the Pt(III),Pt(III) complex [(C6F5)2PtIII(μ-PPh2)2PtIII(C6F5)2](Pt–Pt) (1) with the S-based anions thiophenoxide (PhS–), ethyl xanthogenate (EtOCS2–), 2-mercaptopyrimidinate (pymS–), and 2-mercaptopyridinate (pyS–) was found to be dependent on the reaction solvent. The reactions carried out in acetone led to the formation of [NnBu4][(RF)2PtII(μ-PhS-PPh2)(μ-PPh2)PtII(RF)2] (2), [NnBu4][(RF)2PtII(μ-EtOCS2-PPh2)(μ-PPh2)PtII(RF)2] (3), [NnBu4][(RF)2PtII(μ-pymS-PPh2)(μ-PPh2)PtII(RF)2] (4), and [NnBu4][(RF)2PtII(μ-pyS–PPh2)(μ-PPh2)PtII(RF)2] (5), respectively (RF = C6F5). Complexes 2–5 display new Ph2P(SL) ligands exhibiting a κ2-P,S bridging coordination mode, which is derived from a reductive elimination of a PPh2 group and the S-based anion. Carrying out the reaction in dichloromethane afforded, in the cases of EtOCS2– and pymS–, the monobridged complexes [NnBu4][(PPh2RF)(RF)2PtII(μ-PPh2)PtII(EtOCS2)(RF)] (6) and [NnBu4][(PPh2RF)(RF)2PtII(μ-PPh2)PtII(pymS)(RF)] (7), respectively, which are derived from reductive elimination of a PPh2 group with a pentafluorophenyl ring. The reaction of 1 with EtOCS2K in acetonitrile yielded a mixture of 3 and 6 as a consequence of the concurrence of two processes: (a) the formation of 3 by a reaction that parallels the formation of 3 by 1 plus EtOCS2K in acetone and (b) the transformation of 1 into the neutral complex [(PPh2RF)(CH3CN)(RF)PtII(μ-PPh2)PtII(RF)2(CH3CN)] (8), which, in turn, reacts with EtOCS2K to give 6. The 1 to 8 transformation was found to be fully reversible. In fact, dissolving 8 in acetone or dichloromethane afforded pure 1 after solvent evaporation or crystallization with n-hexane. The XRD structures of 2–4 and 6–8 were determined, and the behavior in solution of the new complexes is discussed., This work was supported by the Spanish MINECO/FEDER (Proyect CTQ2015-67461-P) and the Gobierno de Aragón and Fondo Social Europeo (Grupo Consolidado E21: Química Inorgánica y de los Compuestos Organometálicos).

By employing silver salts with a weakly coordinating anion Ag[A] ([A]=[FAl{OC12F15}(3)], [Al{OC(CF3)(3)}(4)]), two phosphaalkynes could be coordinated side-on to a bare silver-(I) center to form the unprecedented homoleptic complexes [Ag(eta(2)-P equivalent to CtBu)(2)][FAl{OC12F15}(3)] (1) and [Ag(eta(2)-P equivalent to CtBu)(2)]-[Al{OC(CF3)(3)}(4)] (2). DFT calculations show that the perpendicular arrangement in 1 is the minimum energy structure of the coordination of the two phosphaalkynes to a silver atom, whereas for 2 a unique square-planar coordination mode of the phosphaalkynes at Ag+ was found. Reactions with donor molecules yield the trigonally planar coordinated silver salts [((CH3)(2)CO) Ag(eta(2)-P equivalent to CtBu)(2)][FAl{OC12F15}(3)] (3) and [(C7H8)(2)Ag(eta(2)-P equivalent to CtBu)][FAl{OC12F15}(3)] (4). All of the compounds were comprehensively characterized in solution and in the solid state.

Reaction between the phosphinito bridged diplatinum species [(PHCy2 )Pt(mu-PCy2 ){kappa(2) P,O-mu-P(O)Cy2 }Pt(PHCy2 )](Pt-Pt) (1), and (trimethylsilyl)acetylene at 273 K affords the sigma-acetylide complex [(PHCy2 )(eta(1) -Me3 SiC=C)Pt(mu-PCy2 )Pt(PHCy2 ){kappaP-P(OH)Cy2 }](Pt-Pt) (2) featuring an intramolecular pi-type hydrogen bond. Scalar and dipolar couplings involving the POH proton were detected by 2D NMR experiments. Relativistic DFT calculations of the geometry, relative energy, and NMR properties of model systems of 2 confirmed the structural assignment and allowed the energy of the pi-type hydrogen bond to be estimated (ca. 22 kJmol(-1) ).

The carbonylation of the solvento species [(PHCy2)(L)Pt(-PCy2)(-H)Pt(PHCy2){P-P(OH)Cy-2}][BF4](2)(Pt-Pt) ([1-L](2+), L = CH2Cl2, thf, CH3CN) led to the formation of a singly bridged dicarbonyl Pt-I compound syn-[(PHCy2)(CO)Pt(-PCy2)Pt{P-P(OH)Cy-2}(CO)](+)(Pt-Pt) (2(+)). The reaction proceeded in two steps: 1) Substitution of L by CO to give the intermediate syn-[(PHCy2)(CO)Pt(-PCy2)(-H)Pt(PHCy2){P-P(OH)Cy-2}](2+)(Pt-Pt) ([1-CO](2+)) and 2) uptake of a second molecule of CO and elimination of [PH2Cy2](+) (as the BF4- salt) to give 2(+). The dicarbonyl complex [2][BF4] was also synthesized starting from the dicyclohexylphosphanido-bridged complex [(PHCy2)Pt(-PCy2){P-2,O--P(O)Cy-2}Pt(PHCy2)](Pt-Pt) (5). In this case the first step consisted of the carbonylation of 5 to give [(PHCy2)(2)Pt(-PCy2)Pt{P-P(O)Cy-2}(CO)](Pt-Pt) (6), which was transformed into 2(+) by protonation with HBF4 under an atmosphere of CO. Prolonged reaction times for the carbonylation of [1-L](2+) in halogenated solvents resulted in the formation of the symmetrical dicarbonyl compound syn-[(CO)(PHCy2)Pt(-PCy2)Pt(PHCy2)(CO)](+)(Pt-Pt) (3(+)) along with Cy2P(H)OBF3. Complexes 6 and [1-L][BF4](2) were also formed by the carbonylation of 5 and [1-OMe2][BF4](2) in the solid state.

The reaction of (trimethylsilyl)acetylene with the phosphinito phosphanido Pt(I) complex [(PHCy2)Pt(μ-PCy2){κ2P,O-μ-P(O)Cy2}Pt(PHCy2)](Pt-Pt) (1) results in the protonation of the Pt-Pt bond with the formation of the bridging hydride complex [(PHCy2)(Me3SiC≡C)Pt(μ-PCy2)(μ-H) Pt(PHCy2){κP-P(O)Cy2}](Pt-Pt) (2), which was characterized by spectroscopic, spectrometric and XRD analyses. Complex 2 exhibits in the solid state at 77 K a long-lived, weak, orange emission assigned as metal-metal to ligand charge transfer (MMLCT) (L = alkynyl) due to the presence of a very short Pt···Pt distance [2.8209(2) Å]. Reaction of 2 with etherate HBF4 results in the selective protonation of the phosphinito ligand to afford the species [(PHCy2)(Me3SiC≡C)Pt(μ-PCy2)(μ-H) Pt(PHCy2){κP-P(OH)Cy2}](Pt-Pt)[BF4] ([3]BF4).

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)(2)Pt(-PCy2)M-L by reaction either with carbonyl metalates, as metal-based nucleophiles, or with metal-based electrophiles. The heterodinuclear complexes [(PHCy2)(2)Pt(-PCy2)Co(CO)(3)](Pt-Co) (2), [(PHCy2)(2)Pt(-PCy2)Mo(CO)(2)Cp](Pt-Mo) (3), and [(PHCy2)(2)Pt(-PCy2)W(CO)(2)Cp](Pt-W) (4) are obtained by reaction of 1 with the carbonyl metalates Na[Co(CO)(4)], Na[Mo(CO)(3)Cp] and Na[W(CO)(3)Cp], 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(-PCy2)M(CO)(2)Cp] (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 cis- and trans-[{Cl(PHCy2)(2)Pt(-PCy2)}(2)Au]Cl (cis- and trans-[8]Cl), in which a Au atom bridges two molecules of 1 through the originally terminal phosphanide ligands.

The reactions of [Ag(OClO3)(PPh3)] with [NBu 4][(C6F5)2Pt(μ-PPh 2)2M(hq)], [NBu4][(C6F 5)2Pt(μ-PPh2)2M(bq)], [NBu 4][(C6F5)2Pt(μ-PPh 2)2M(pic)] and [NBu4][(C6F 5)2Pt(μ-PPh2)2Pt(C 6F5)(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) [(C 6F5)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. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., This work was supported by the Spanish Ministerio de Ciencia e Innovación (MICINN), DGPTC/FEDER (project number CTQ2008-06669-C02-01/BQU), Ministerio de Economía y Competitividad (MINECO)/FEDER (project number CTQ2012-35251) and the Gobierno de Aragón (Grupo Consolidado E21: Química Inorgánica y de los Compuestos Organometálicos). A. A. gratefully acknowledges MICINN for an FPU grant. The Italian Ministero dell’Università e della Ricerca (MIUR) (PRIN project number 2009LR88XR) is also acknowledged for financial support.

The dinuclear anionic complexes [NBu4][(RF) 2MII(μ-PPh2)2M′ II(N∥O)] (RF = C6F5. N∥O = 8-hydroxyquinolinate, hq; M = M′ = Pt 1; Pd 2; M = Pt, M′ = Pd, 3. N∥O = o-picolinate, pic; M = Pt, M′ = Pt, 4; Pd, 5) are synthesized from the tetranuclear [NBu4] 2[{(RF)2Pt(μ-PPh2) 2M(μ-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-[(RF) 2M(μ-PPh2)2]2-> and >M′(N∥O)> (2 and 3). The electrochemical oxidation of the anionic complexes 1-5 occurring under HRMS(+) conditions gave the cations [(RF)2M(μ-PPh2) 2M′(N∥O)]+, presumably endowed with a M(III),M′(III) core. The oxidative addition of I2 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 [(RF)2MII(μ-I)(μ-PPh 2)M′II(P,N-PPh2hq)], 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 I2 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-OC 6H4NO (Ph2P-pic). In these cases, the isolated derivatives [NBu4][(Ph2P-pic)(RF)Pt II(μ-I)(μ-PPh2)MII(RF)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 I2 to [NBu4][(RF)2PtII(μ-PPh 2)2PtII(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][(RF)2PtII(μ-I)(μ- PPh2)PtII(Ph2P-acac)I] (12). The transformations of the starting complexes into the products containing the P-O ligands passes through mixed valence M(II),M′(IV) intermediates which were detected, for M = M′ = Pt, by spectroscopic and spectrometric measurements. © 2013 American Chemical Society., This work was supported by the Spanish MICINN (Project CTQ2008-06669-C02-01), the Ministerio de Economía y Competitividad (Project CTQ2012-35251), and the Cobierno de Aragón (Grupo de Consolidado: Quimíca Inorgánica y de los Compuestos Organometálicos). A.A. gratefully acknowledges MICINN for a FPU grant. Italian MIUR (PRIN project n. 2009LR88XR) is also acknowledged for financial support.

The reactivity of the dinuclear platinum(III) derivative [(R F)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[(R F)2PtII(μ-OPPh2)(μ-PPh 2)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][(R F)2PtII(μ-N3)(μ-PPh 2)PtII(RF)(PPh2RF)] (4b). Analogous behavior was shown in the addition of NCO- to 1 which afforded [NBu4]2[(RF)2Pt II(μ-NCO)(μ-PPh2)PtII(RF) 2] (5a) and [NBu4][(RF)2Pt II(μ-NCO)(μ-PPh2)PtII(R F)(PPh2RF)] (5b). In the reaction of the trinuclear complex [(RF)2PtIII(μ-PPh 2)2PtIII(μ-PPh2) 2PtII(RF)2](PtIII-Pt III) (2) with OH- or N3 -, the coordination of the nucleophile takes place selectively at the central platinum(III) center, and the PPh2/OH- or PPh 2/N3 - reductive coupling yields the trinuclear [NBu4]2[(RF)2PtII(μ- Ph2PO)(μ-PPh2)PtII(μ-PPh 2)2PtII(RF)2] (6) and [NBu4][(RF)2Pt1(μ3- Ph2PNPPh2)(μ-PPh2)Pt2(μ- PPh2)Pt3(RF)2](Pt 2-Pt3) (7). Complex 7 is fluxional in solution, and an equilibrium consisting of Pt-Pt bond migration was ascertained by 31P EXSY experiments. © 2013 American Chemical Society., This work was supported by the Spanish MICINN (DGPTC)/FEDER (Project CTQ2008-06669-C02-01/BQU), MINECO/FEDER (Project CTQ2012-35251), the Gobierno de Aragón (Grupo de Consolidado E21: Quımíca Inorgánica y de los Compuestos Organometálicos), and the Italian MIUR (PRIN project n. 2009LR88XR). A.A. gratefully acknowledges MICINN for an FPU grant.

Fast oxidations of the iron(II)N,N-dialkylcarbamato complexes [Fe(II)(O2CNR2)(2)](n) (R = Et, n = 6, 1; R = Pr-i, 2) and [Fe(II)(8)(mu(4)-O)(2)((O2CNPr2)-Pr-i)(12)], 3, by dioxygen were carried out both in an anhydrous hydrocarbon and in the solid state affording [Fe(III)(2)(O)(O2CNR2)(4)](x), 7 and 8 for R = Et and Pr-i, respectively, and [Fe(III)(4)(O)(3) ((O2CNPr2)-Pr-i)(6)](y), 9. The stoichiometric O-2 uptake was not accompanied by oxidation of the ligand. Recovery of unchanged starting material was observed when the manganese(II) derivatives [Mn(II)(O2CNR2)(2)](n) (R = Et, n = 6, 4; R = Pr-i, 5) were treated with O-2. Nevertheless, when [Mn(II)(8)(mu(4)-O)(2)((O2CNPr2)-Pr-i)(12)], 6, prepared in situ by reaction of 5 with water (Mn/H2O molar ratio = 4), was reacted with O-2, complete oxidation occurred to a product where manganese showed an average. oxidation number III, [Mn(III)(4)(O)(3) ((O2CNPr2)-Pr-i)(6)](y), 10. The product [Mn(II)(6)Mn(III)(2)(mu(4)-O)(2)(mu(3)-O)((O2CNPr2)-Pr-i)(12)], 11, obtained by partial oxidation of 6 by 02, has been characterised by X-ray diffraction methods. (C) 2013 Elsevier Ltd. All rights reserved.

The rational synthesis of dinuclear asymmetric phosphanido derivatives of palladium and platinum(II), [NBu4][(RF)2M(μ-PPh2)2M′(κ2,N,C-C13H8N)] (RF = C6F5; M = M′ = Pt, 1; M = Pt, M′ = Pd, 2; M = Pd, M′ = Pt, 3; M = M′ = Pd, 4), is described. Addition of I2 to 1–4 gives complexes [(RF)2MII(μ-PPh2)(μ-I)PdII{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/C∧N reductive coupling on the mixed valence M(II)–M′(IV) [NBu4][(RF)2MII(μ-PPh2)2M′IV(κ2,N,C- C13H8N)I2] complexes, which were identified for MII = Pd, M′IV = Pt (9), and isolated for MII = 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., This work was supported by the Spanish MICINN (Project CTQ2008-06669-C02-01) and the Gobierno de Aragón (Grupo Consolidado: Química Inorgánica y de los Compuestos Organometálicos). A.A. gratefully acknowledges MICINN for an FPU grant. COST Action CM0802 “PhoSciNet” and Italian MIUR (PRIN Project 2009LR88XR) are also acknowledged for financial support.

The reactivity of the complexes [PtCl(2){Ph(2)PN(R)PPh(2)-P,P}] (R = -H, 3; R = -(CH(2))(9)CH(3), 8) toward group 6 carbonylmetalates Na[MCp(CO)(3)] (M = W or Mo, Cp = cyclopentadienyl) was explored. When R = H, the triangular clusters [PtM(2)Cp(2)(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 = -(CH(2))(9)CH(3), isomeric mixtures of the triangular clusters [PtM(2)Cp(2)(CO)(5){Ph(2)PN(R)PPh(2)-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 = -(CH(2))(9)CH(3), the reaction of [PtCl(2){Ph(2)PN(R)PPh(2)-P,P}] with Na[MCp(CO)(3)] in acetonitrile stopped at the monosubstitution stage with the formation of [PtCl{MCp(CO)(3)}{Ph(2)PN(R)PPh(2)-P,P}] (R = -(CH(2))(9)CH(3), 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.