Axial chirality and supramolecular interactions: the case of [(kappa2-P,P-[PPh2NMe]2CO)Cu(I)Cl]2

The title compound [(kappa2-P,P-[PPh(2)NMe}2CO)Cu(I)Cl]2 (4) is readily formed by the reaction between (PPh2NMe)2CO and copper(I) chloride. Compound 4 forms a two-dimensional supramolecular network of Cu2Cl2-centered dimers that are linked by pi-pi interaction between the phenyl substituents on phosphorus in the solid state. Because of the nature of these pi-pi interactions, only one of the three possible enantiomers, the meso form, can be observed in the crystals.     

Diverse evolution of [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 2, 3) metalloligands in CH(2)Cl(2)

The nucleophilicity of the [Pt(2)S(2)] core in [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 3, dppp (1); n = 2, dppe (2)) metalloligands toward the CH(2)Cl(2) solvent has been thoroughly studied. Complex 1, which has been obtained and characterized by X-ray diffraction, is structurally related to 2 and consists of dinuclear molecules with a hinged [Pt(2)S(2)] central ring. The reaction of 1 and 2 with CH(2)Cl(2) has been followed by means of (31)P, (1)H, and (13)C NMR, electrospray ionization mass spectrometry, and X-ray data. Although both reactions proceed at different rates, the first steps are common and lead to a mixture of the corresponding mononuclear complexes [Pt[Ph(2)P(CH(2))(n)PPh(2)](S(2)CH(2))], n = 3 (7), 2 (8), and [Pt[Ph(2)P(CH(2))(n)PPh(2)]Cl(2)], n = 3 (9), 2 (10). Theoretical calculations give support to the proposed pathway for the disintegration process of the [Pt(2)S(2)] ring. Only in the case of 1, the reaction proceeds further yielding [Pt(2)(dppp)(2)[mu-(SCH(2)SCH(2)S)-S,S']]Cl(2) (11). To confirm the sequence of the reactions leading from 1 and 2 to the final products 9 and 11 or 8 and 10, respectively, complexes 7, 8, and 11 have been synthesized and structurally characterized. Additional experiments have allowed elucidation of the reaction mechanism involved from 7 to 11, and thus, the origin of the CH(2) groups that participate in the expansion of the (SCH(2)S)(2-) ligand in 7 to afford the bridging (SCH(2)SCH(2)S)(2-) ligand in 11 has been established. The X-ray structure of 11 is totally unprecedented and consists of a hinged [(dppp)Pt(mu-S)(2)Pt(dppp)] core capped by a CH(2)SCH(2) fragment.     

Diphenyldichlorophosphonium trichloride-chlorine solvate 1:1, [PPh2Cl2]+Cl(3)(-).Cl2: an ionic form of diphenyltrichlorophosphorane. Crystal structures of [PPh2Cl2]+Cl(3)(-).Cl2 and [(PPh2Cl2)+]2[InCl5](2-)

An ionic form of diphenyltrichlorophosphorane, namely, diphenyldichlorophosphonium trichloride isolated as a dichlorine solvate (1), was obtained by treating PPh(2)Cl(3) with excess chlorine. The identity of this species was established by single-crystal X-ray analysis and (31)P, (1)H, and (35)Cl NMR and Raman spectra. Bis(diphenyldichlorophosphonium) pentachloroindate (2) was obtained by the reaction of diphenyltrichlorophosphorane with indium trichloride in dichloromethane for comparison purposes. Its identity was determined by (31)P NMR spectra and single-crystal X-ray analysis.     

Unique Pt5 metallacycle: [Pt(II)Cl(pyrrolidinedithiocarbamate)]5

The neutral complex [PtCl(PyDT)](5) (PyDT = (CH(2))(4)NCS(2)(-)) represents the first example of a Pt(5) metallacycle. This unique architecture based on chiral S-bridged Pt(II) monomers was prepared by thermal degradation of the reaction product of PtCl(2) and a pyrrolidinedithioester.     

醇蒸气发光敏感器用聚4-乙烯基吡啶铂（Ⅱ）配合物的研究

将小分子金属配合物[Pt(C^N^N)Cl](HC^N^N=6-(4-苯基)-2,2′-联吡啶)连接到高分子P4VP(聚4-乙烯基吡啶)侧链上,制备了聚4-乙烯基吡啶铂(Ⅱ)配合物[(P4VP)Pt(C^N^N)]Cl。此高分子配合物旋涂膜对醇蒸气具有高度的识别响应能力:膜的荧光强度在醇蒸气中迅速猝灭。而在氮气流中,荧光又能够重新开启。整个过程可逆、迅速。膜对不同醇蒸气的敏感能力差别顺序为:甲醇>乙醇>异丙醇。并且荧光强度变化和醇蒸气浓度在一定范围内,具有好的线性关系。此外膜对以上醇蒸气的监测LOD(limit of detection)分别是9.5、16.1和11 ppm。     

The platinum—carbon bond strength in Pt(PPh3)2(Cl)(CPhCHPh)

The enthalpies of the reactions 1 and 2 have been determined as ΔH = Pt(PPh₃)₂(CPhCPh)_cryst. + HCl_g → Pt(PPh₃)₂(Cl)(CPhCHPh)_cryst. (1) Pt(PPh₃)₂(CPhCPh)_cryst. + 2HCl_g → cis-Pt(PPh₃)₂Cl_2cryst. + trans-CHPhCHPh_g (2) ?90.2 ± 6 and ΔH = ?139.0 ± 16 kJ mol^?1, respectively; dissociation energies of bonds involving platinum are expressed by the relationship: 41 kJ mol^?1 + D(Pt-tolane) = 2D(PtCPhCHPh) = {D₁(PtCl) + D₂(PtCl)} ?350 kJ mol^?1     

Carbonyl complexes of platinum(0): synthesis and structure of [(Cy3P)2Pt(CO)] and [(Cy3P)2Pt(CO)2

The platinum(0) monocarbonyl complex, [(Cy(3)P)(2)Pt(CO)], was synthesized by reaction of [(Cy(3)P)(2)Pt] with [(η(5)-C(5)Me(5))Ir(CO)(2)] and subsequent irradiation. X-ray structure analysis was performed and represents the first structural evidence of a platinum(0) monocarbonyl complex bearing two free phosphine ligands. Its corresponding dicarbonyl complex [(Cy(3)P)(2)Pt(CO)(2)] was synthesized by treatment of [(Cy(3)P)(2)Pt] with CO at -40 °C and confirmed by X-ray structure analysis.     

Syntheses of Trifluoromethanethiolato Platinum(II) Complexes – Crystal Structures of cis‐Pt(SCF3)2(PPh3)2 and trans‐Pt(SCF3)Cl(PPh3)2

Ligand exchange reactions of cis‐PtCl₂(PPh₃)₂ and [NMe₄]SCF₃ in different ratios were studied. Depending on the stoichiometry reactions proceeded with formation of products expected for the chosen ratio, i. e. cis‐Pt(SCF₃)Cl(PPh₃)₂, cis‐Pt(SCF₃)₂(PPh₃)₂, and [NMe₄][Pt(SCF₃)₃(PPh₃)]. Starting from cis‐PtCl₂(MeCN)₂ and [NMe₄]SCF₃ and adding PPh₃ after substitution, product mixtures were dominated by the corresponding trans‐isomers. Results of the single crystal structure analyses of cis‐Pt(SCF₃)₂(PPh₃)₂ and trans‐Pt(SCF₃)Cl(PPh₃)₂ are discussed.     

Strength of the PtCS2 bond in Pt(PPh3)2(CS2)

The enthalpy of the reaction: Pt(PPh₃)₂(CH₂CH₂)(cryst.) + CS₂(g) → Pt(PPh₃)₂(CS₂)(cryst.) + CH₂CH₂(g) has been determined as ΔH = ? 4.40 ± 2.2 kJ mol^?1 from solution calorimetry, and the bond dissociation energy D(PtCS₂) shown to be slightly greater than D(PtC₂H₄).     

Generation of [(IPr)Pd(PR2Cl)] complexes via P-Cl reductive elimination

Treatment of [(IPr)Pd(Cl)(2)(PR(2)H)] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; R = Cy, tBu, or 1-Ad) with NaN(SiMe(3))(2) generated isolable [(IPr)Pd(PR(2)Cl)] complexes (68-75%) that have been crystallographically characterized. The formation of these mixed-ligand Pd(0) species in this manner corresponds to an unusual net dehydrohalogenation/P-Cl reductive elimination sequence.     

The pentacoordinate titanium complex [TiCl2(NMe2)2(HNMe2)]

Amido complexes of titanium are useful reagents in a variety of syntheses and as precursors for chemical vapour deposition of TiN. The title compound, di­chloro­bis­(di­methyl­amido)(di­methyl­amine)­titanium(IV), [TiCl₂(C₂H₆N)₂(C₂H₇N)], crystallizes with one mol­ecule in the asymmetric unit. The neutral complex shows an unusual fivefold coordination of the titanium centre with a distorted trigonal–bipyramidal geometry and the di­methyl­amine mol­ecule occupying an axial position.     

Addukte des Oxo-tetrachloro-niobat(V)-Ions Bildung,Schwingungsspektren und Kristallstrukturen von PPh4[NbOCl4(OH2)] und (PPh4)2[NbOCl4(O2PCl2)] · 2 CH2Cl2

Adducts of Oxotetrachloro-niobate (V). Formation, Vibrational Spectra, and Crystal Structures of PPh₄[NbOCl₄(OH₂)] and (PPh₄)₂[NbOCl₄(O₂PCl₂)] · 2 CH₂Cl₂ Crystalline (PPh₄)₂[NbOCl₄(O₂PCl₂)] · 2 CH₂Cl₂ was obtained by hydrolysis of PPh₄[NbSCl₄] in the presence of POCl₃ in CH₂Cl₂. Experiments to obtain the same compound from PPh₄Cl, POCl₃, NbCl₅, and H₂O yielded PPh₄[NbOCl₄(OH₂)]. I.R. spectra of both compounds are discussed. The crystal structure determinations with X-ray diffraction data in both cases show quadratic-pyramidal NbOCl₄^? ions to which a molecule of either H₂O or a PO₂Cl₂^? ion is attached in trans-position to the O atom. PPh₄[NbOCl₄(OH₂)]: tetragonal, space group P4/n, a = 1 308, c = 734 pm, Z = 2, packing as in the AsPh₄[RuNCl₄] type; refinement down to R = 0.046 for 681 reflexions. (PPh₄)₂[NbOCl₄(O₂PCl₂)] · 2 CH₂Cl₂: triclinic, space group P1 , a = 1172, b = 1187, c = 2105 pm, α = 88.40, β = 83.20, γ = 71.28°, Z = 2, packing similar as in (AsPh₄)₂[NbOCl₅] · 2 CH₂Cl₂; refinement to R = 0.059 for 2 502 reflexions.     

A multinuclear NMR study of [Pt0(PPh3)2(alkene)] compounds containing asymmetric olefins

The 1H, 13C, 31P, and 195Pt NMR spectra of [Pt0(PPh3)2(eta-ABC(1) = C(2)XY)] compounds (ABC(1)= C(2)XY (1) A = B = X = Y = H; (3) A = B = X = H, Y = CN; (4) A = H, B = p-NO2-Ph, X = COOCH3, Y = CN; (5) A = H, B = Ph, X = COOCH3, Y = CN; (6) A = H, B = Ph, X = Y = CN; (7) A = H, B = OEt, X = Y = CN), where X and Y are electronacceptor substituents, and the 1H spectrum of [Pt0(PPh3)2(eta2-C60)] (2) are reported together with extended analyses and assignments, based also on the ring current effect of the olefin phenyl in (4-6). Deviations from first order in the 13C spectra allowed the determination of the relative signs of the coupling constants J(P(1), C) and J(P(2), C) of the alkene and of the triphenylphosphine carbons. Best fit simulation of the phosphine C ipso spectrum provided also the 13C isotopic shift on phosphorus for (1). These compounds are characterised by strong differences between the two platinum-phosphorus coupling constants in the case of asymmetric olefins (3-7). The chemical shifts of alkene C(1) and C(2) indicate notable polarisation of the olefin after complexation, while the 1J(Pt, C(1)) and 1J(Pt, C(2)) values are in agreement with a stronger interaction of Pt with C(1) than with C(2). These findings together with the trend of 195Pt chemical shifts confirm the important role played by back-donation in the bonding of platinum(0)-olefin compounds.     

Silyl,hydrido-silylene,or other bonding modes: some unusual structures of [(dhpe)Pt(SiHR2)]+ (dhpe = H2P-CH2-CH2-PH2; R = H,Me, SiH3, Cl,OMe, NMe2) and [(dhpe)Pt(SiR3)](+) (R = Me,Cl) from DFT calculations

DFT (B3LYP) calculations have been carried out in order to quantitatively evaluate the energies and stereochemistry of the accessible structures of [(dhpe)Pt(SiHR(2))](+) (dhpe = H(2)P-CH(2)-CH(2)-PH(2); R = H, CH(3), SiH(3), Cl, OMe, SMe, NMe(2)) and of [(dhpe)Pt(SiR(3))](+) (R = CH(3), Cl). A number of different isomers have been located. The expected terminal silyl or hydrido-silylene complexes are often not the most stable complexes. An isomer in which an H or an R group bridges a Pt=SiHR or Pt=SiR(2) bond is found to compete with the terminal silyl or hydrido-silylene isomers. In some cases, isomers derived from cleavage of a C-H bond and formation of a silene or disilene ligand are obtained. The structures of the platinum silyls differ from that of the equivalent alkyl complex, calculated for [(dhpe)Pt(CH(3))](+).     

N(B(NMe2)2)(Si(NMe2)3)(Ti(NMe2)3), [N(Si(NMe2)3)(Ti(NMe2)2)]2 und N(SiMe3)(Si(NMe2)3)(Ti(NMe2)3) — Synthese und Charakterisierung neuer molekularer Einkomponentenvorläufer für nitridische und carbonitridische Keramiken

N(B(NMe₂)₂)(Si(NMe₂)₃) (Ti(NMe₂)₃), [N(Si(NMe₂)₃)(Ti(NMe₂)₂)]₂ und N(SiMe₃)(Si(NMe₂)₃)(Ti(NMe₂)₃) — Synthesis and Characterization of New Molecular Single-source Precursors for Nitride and Carbonitride Ceramics Synthesis and spectroscopic data of the title compounds are reported. [N(Si(NMe₂)₃)(Ti(NMe₂)₂)]₂ crystallizes in the space group P1 , a = 8.406(7), b = 10.673(8), c = 10.872(6) Å, α = 68.45(4)°, β = 71.72(4)°, γ = 78.11(7)°, 2 877 diffractometer data (F_o ? 2σF_o), R = 0.051. The compound is characterized by a planar four-membered Ti₂N₂-ring with exocyclic tris(dimethylamino)silyl substituents attached to the nitrogen atoms of the ring.