On the Reactivity of the Platina‐β‐diketone [Pt2{(COMe)2H}2(μ‐Cl)2] Towards Ph2PCH2CH2CH2SOxPh (x = 0, 2)

The reaction of the electronically unsaturated platina‐β‐diketone [Pt₂{(COMe)₂H}₂(μ‐Cl)₂] ( 1 ) with Ph₂PCH₂CH₂CH₂SPh ( 2 ) leads selectively to the formation of the acetyl(chlorido) platinum(II) complex (SP‐4‐3)‐[Pt(COMe)Cl(Ph₂PCH₂CH₂CH₂SPh‐κP,κS)] ( 4 ) having the γ‐phosphinofunctionalized propyl phenyl sulfide coordinated in a bidentate fashion (κP,κS). In boiling benzene complex 4 undergoes decarbonylation yielding the methyl(chlorido) platinum(II) complex (SP‐4‐3)‐[PtMeCl(Ph₂PCH₂CH₂CH₂SPh‐κP,κS)] ( 6 ). However, the reaction of 1 with the analogous γ‐diphenylphosphinofunctionalized propyl phenyl sulfone Ph₂PCH₂CH₂CH₂SO₂Ph ( 3 ) affords the acetyl(chlorido) platinum(II) complex (SP‐4‐4)‐[Pt(COMe)Cl(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂] ( 5 ). In boiling benzene complex 5 undergoes a CO extrusion yielding (SP‐4‐4)‐[PtMeCl(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂] ( 8 ) whereas in presence of 1 the formation of the carbonyl complex (SP‐4‐3)‐[PtMeCl(CO)(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)] ( 7 ) is observed. Addition of Ag[BF₄] to complex 5 leads to the formation of the cationic methyl(carbonyl) platinum(II) complex (SP‐4‐1)‐[PtMe(CO)(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂][BF₄] ( 9 ). All complexes were characterized by microanalysis and NMR spectroscopy (¹H, ¹³C, ³¹P) and complexes 4 and 6 additionally by single‐crystal X‐ray diffraction analyses.     

Synthesis and characterization of adducts of dichlorosulphato bis(1,3-propylenediamine)metal(II) complexes with dialkyltin dichlorides

Summary Adducts of dichlorosulphato bis(1,3-propylenediamine)-metal(II) complexes with dialkyltin dichlorides, [R₂Sn(MeCN) ₂]₂[M(NH(CH₂)₃NH)₂(SO₃Cl)₂] (M = Cr, Fe, Co, Ni or Cu; R = Me or n-Bu) have been prepared. The positive shift in the symmetric SO₃ stretch and splitting of the doubly degenerate (E) modes in their i.r. spectra suggest a covalent linkage for the SO₃Cl^– group. The adducts are non-electrolytes; magnetic moments and ligand field data suggest that each SO₃Cl^– group is monodentate, generating an octahedral geometry around the metal ions, except for Ni^II where tetragonal distortion is observed.Author to whom all correspondence should be directed.     

Electrochemical and Theoretical Investigations of the Role of the Appended Base on the Reduction of Protons by [Fe2(CO)4(κ2‐PNPR)(μ‐S(CH2)3S] (PNPR={Ph2PCH2}2NR,R=Me,Ph)

The behavior of [Fe₂(CO)₄(κ²‐PNP^R)(μ‐pdt)] (PNP^R=(Ph₂PCH₂)₂NR, R=Me ( 1 ), Ph ( 2 ); pdt=S(CH₂)₃S) in the presence of acids is investigated experimentally and theoretically (using density functional theory) in order to determine the mechanisms of the proton reduction steps supported by these complexes, and to assess the role of the PNP^R appended base in these processes for different redox states of the metal centers. The nature of the R substituent of the nitrogen base does not substantially affect the course of the protonation of the neutral complex by CF₃SO₃H or CH₃SO₃H; the cation with a bridging hydride ligand, 1 μH⁺ (R=Me) or 2 μH⁺ (R=Ph) is obtained rapidly. Only 1 μH⁺ can be protonated at the nitrogen atom of the PNP chelate by HBF₄?Et₂O or CF₃SO₃H, which results in a positive shift of the proton reduction by approximately 0.15 V. The theoretical study demonstrates that in this process, dihydrogen can be released from a η²‐H₂ species in the Fe^IFe^II state. When R=Ph, the bridging hydride cation 2 μH⁺ cannot be protonated at the amine function by HBF₄?Et₂O or CF₃SO₃H, and protonation at the N atom of the one‐electron reduced analogue is also less favored than that of a S atom of the partially de‐coordinated dithiolate bridge. In this situation, proton reduction occurs at the potential of the bridging hydride cation, 2 μH⁺ . The rate constants of the overall proton reduction processes are small for both complexes 1 and 2 (k_obs≈4–7 s^?1) because of the slow intramolecular proton migration and H₂ release steps identified by the theoretical study.     

Facile Synthetic Access to Rhenium(II) Complexes: Activation of Carbon–Bromine Bonds by Single‐Electron Transfer

The five‐coordinated Re^I hydride complexes [Re(Br)(H)(NO)(PR₃)₂] (R=Cy 1 a , iPr 1 b ) were reacted with benzylbromide, thereby affording the 17‐electron mononuclear Re^II hydride complexes [Re(Br)₂(H)(NO)(PR₃)₂] (R=Cy 3 a , iPr 3 b ), which were characterized by EPR, cyclic voltammetry, and magnetic susceptibility measurements. In the case of dibromomethane or bromoform, the reaction of 1 afforded Re^II hydrides 3 in addition to Re^I carbene hydrides [Re(?CHR¹)(Br)(H)(NO)(PR₃)₂] (R¹=H 4 , Br 5 ; R=Cy a , iPr b ) in which the hydride ligand is positioned cis to the carbene ligand. For comparison, the dihydrogen Re^I dibromide complexes [Re(Br)₂(NO)(PR₃)₂(η²‐H₂)] (R=Cy 2 a , iPr 2 b ) were reacted with allyl‐ or benzylbromide, thereby affording the monophosphine Re^II complex salts [R₃PCH₂R′][Re(Br)₄(NO)(PR₃)] (R′=? CH?CH₂ 6 , Ph 7 ). The reduction of Re^II complexes has also been examined. Complex 3 a or 3 b can be reduced by zinc to afford 1 a or 1 b in high yield. Under catalytic conditions, this reaction enables homocoupling of benzylbromide (turnover frequency (TOF): 3 a 150, 3 b 134 h^?1) or allylbromide (TOF: 3 a 575, 3 b 562 h^?1). The reaction of 6 a and 6 b with zinc in acetonitrile affords in good yields the monophosphine Re^I complexes [Re(Br)₂(NO)(MeCN)₂(PR₃)] (R=Cy 8 a , iPr 8 b ), which showed high catalytic activity toward highly selective dehydrogenative silylation of styrenes (maximum TOF of 61 h^?1). Single‐electron transfer (SET) mechanisms were proposed for all these transformations. The molecular structures of 3 a , 6 a , 6 b , 7 a , 7 b , and 8 a were established by single‐crystal X‐ray diffraction studies.     

Metal complexes of ligands containing intercalating units. Synthesis of nickel(II), copper(II), rhodium(II), and platinum(II) complexes with diamine-substituted acridines and quinolines,and with mitonafide [N-(2,2-dimethylaminoethyl)-3-nitro-1, 8-naphthalimide] and related ligands

Summary The preparations and characterisation are reported of a range of complexes of Ni^II, Cu^II, Rh^II, and Pt^II with 6-chloro-2-methoxyacridine substituted in the 9-position with –NH(CH₂)_nNR₂ groups (where n=2 or 3, R=H or Me), and of complexes with 7-chloroquinoline analogously substituted in the 4-position. The preparations are also reported of complexes of the types [Rh(CH₃CO₂)₂L]₂, Cu(CH₃CO₂)₂L₂, PtL₂Cl₂, and (LH)₂[PtCl₄], where L=N-(2,2-dimethylaminoethyl)-3-nitro-1, 8-naphthalimide (mitonafide) and/or its 2,2-aminoethyl-, 2,2-aminopropyl-, or 2,2-dimethylaminopropyl analogues. Initial cytotoxicity studies are reported for some of the Pt compounds.     

Study on the reactions of the dinitrogen complexestrans-[M(N2)2(Ph 2PCH2CH2PPh 2)2] (M=Mo or W) with ethyldiazoacetate: Formation of an Azo compound and of a phosphazene species

Complextrans-[Mo(N₂)₂(dppe)₂] (dppe=Ph ₂PCH₂CH₂PPh ₂) reacts with NN=CHCOOEt in benzene solution to afford benzene-azomethane,Ph-N=N-CH₃, as the main organic product. However, the phosphazene speciesPh ₂P(N₂CHCOOEt)(CH₂CH₂)P(N₂CHCOOEt)Ph ₂ is formed by irradiating aTHF solution oftrans-[W(N₂)₂(dppe)₂] in the presence of ethyldiazoacetate; in moist solution, the phosphazene bonds undergo a partial hydrolysis, and the phosphonium species [Ph ₂P(NHNCHCOOEt)(CH₂CH₂)P(NHNCHCOOEt)Ph ₂]²⁺ appears to be formed.

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Untersuchungen zu den Reaktionen der Distickstoff-Komplexetrans-[M(N₂)₂(Ph ₂PCH₂CH₂PPh ₂)₂] (M=Mo oder W) mit Ethyldiazoacetat: Die Bildung einer Azoverbindung und eines Phosphazens

Zusammenfassung Die Komplexetrans-[Mo(N₂)₂(dppe)₂] (dppe=Ph ₂PCH₂CH₂PPh ₂) reagieren mit NN=CHCOOEt in benzolischer Lösung zuPh-N=N-CH₃ als organischem Hauptprodukt. Andererseits wird bei der Bestrahlung vontrans-[W(N₂)₂(dppe)₂] inTHF-Lösung in der Gegenwart von Ethyldiazoacetat das PhosphazenPh ₂P(N₂CHCOOEt)(CH₂CH₂)P(N₂CHCOOEt)Ph ₂ gebildet; in feuchter Lösung erleidet die Phosphazen-Bindung eine teilweise Hydrolyse und die Phosphonium-Spezies [Ph ₂P(NHNCHCOOEt)(CH₂CH₂)P(NHNCHCOOEt)Ph ₂]²⁺ scheint gebildet zu werden.

     

Ligand behaviour of P-functionally substituted organotin halides: palladium(II) and platinum(II) complexes with Ph2PCH2CH2SnCl3

The P-functional organotin chloride Ph₂PCH₂CH₂SnCl₃ reacts with [(COD)MCl₂] and trans-[(Et₂S)₂MCl₂] (M=Pd, Pt) in molar ratio 1:1 to the zwitterionic complexes [(COD)M⁺(Cl)(PPh₂CH₂CH₂Sn⁻Cl₄)] (1: M=Pd; 2: M=Pt) and trans-[(Et₂S)₂M⁺(Cl)(PPh₂CH₂CH₂Sn⁻Cl₄)] (3: M=Pd; 4: M=Pt). The same reaction with [(COD)Pd(Cl)Me] yields under transfer of the methyl group from palladium to tin the complex [(COD)M⁺(Cl)(PPh₂CH₂CH₂Sn⁻MeCl₃)] (5) which changes in acetone into the dimeric adduct [Cl₂Pd(PPh₂CH₂CH₂SnMeCl₂·2Me₂CO)]₂ (6). In molar ratio 2:1 Ph₂PCH₂CH₂SnCl₃ reacts with [(COD)MCl₂] to the complexes [Cl₂Pd(PPh₂CH₂CH₂SnCl₃)₂] (7: M=Pd, mixture of cis/trans isomer; 8: M=Pt, cis isomer). In a subsequent reaction 8 is transformed in acetone into the 16-membered heterocyclic complex cis-[Cl₂Pt(PPh₂CH₂CH₂)₂SnCl₂]₂ (9). trans-[(Et₂S)₂PtCl₂] and Ph₂PCH₂CH₂SnCl₃ in molar ratio 1:2 yields the zwitterionic complex [(Et₂S)M⁺(Cl)(PPh₂CH₂CH₂SnCl₃)(PPh₂CH₂CH₂Sn⁻Cl₄)] (10). The results of crystal structure analyses of 1, 3, 6, 9 and of the adduct of the trans-isomer of 7 with acetone (7a) are reported. ³¹P- and ¹¹⁹Sn-NMR data of the complexes are discussed.     

Bis(arylimido) Molybdenum(VI) Amidinate and Guanidinate Complexes; Molecular Structures of [(ArN)2MoMe{N(Cy)C[N(i‐Pr)2]N(Cy)}] (Ar = 2,6‐i‐Pr2C6H3; Cy = Cyclohexyl) and [(2,6‐i‐Pr2C6H3N)2MoCl2] · [NH=C(C6H5)CH(SiMe3)2]

The reaction of [(ArN)₂MoCl₂] · DME (Ar = 2,6‐i‐Pr₂C₆H₃) ( 1 ) with lithium amidinates or guanidinates resulted in molybdenum(VI) complexes [(ArN)₂MoCl{N(R¹)C(R²)N(R¹)}] (R¹ = Cy (cyclohexyl), R² = Me ( 2 ); R¹ = Cy, R² = N(i‐Pr)₂ ( 3 ); R¹ = Cy, R² = N(SiMe₃)₂ ( 4 ); R¹ = SiMe₃, R² = C₆H₅ ( 5 )) with five coordinated molybdenum atoms. Methylation of these compounds was exemplified by the reactions of 2 and 3 with MeLi affording the corresponding methylates [(ArN)₂MoMe{N(R¹)C(R²)N(R¹)}] (R¹ = Cy, R² = Me ( 6 ); R¹ = Cy, R² = N(i‐Pr)₂ ( 7 )). The analogous reaction of 1 with bulky [N(SiMe₃)C(C₆H₅)C(SiMe₃)₂]Li · THF did not give the corresponding metathesis product, but a Schiff base adduct [(ArN)₂MoCl₂] · [NH=C(C₆H₅)CH(SiMe₃)₂] ( 8 ) in low yield. The molecular structures of 7 and 8 are established by the X‐ray single crystal structural analysis.     

Kinetics and mechanism of palladium(II) catalysed oxidation of amines and aminoalcohols by N-bromosuccinimide in perchloric acid

Summary The kinetics of oxidation of amines (EtNH₂, Et₂NH, Et₃N) and aminoalcohols [H₂NCH₂CH₂OH, H₂N(CH₂)₃OH, (CH₂CH₂OH)₂NH, (CH₂CH₂OH)₃N] by N-bromosuccinimide (NBS) have been studied in aqueous HClO₄ with PdCl₂ as catalyst, and in the presence of Hg(OAc)₂ to ensure oxidation by pure NBS. The order of reaction with respect to NBS was unity, however, an increase in [NBS]₀ resulted in a decrease in the rate constant. The rate was directly proportional to [Pd^II] for the aminoalcohols while for EtNH₂ the rate was proportional to k + k[Pd^II] (where k and k are rate constants for the uncatalysed and catalysed paths, respectively). Retarding effects for HClO₄, succinimide, Cl^– and AcOH on the rate of oxidation were observed. The kinetic data support the formation of [Pd^II-A] and [Pd^II-(A)₂] complexes (where A represents amine or aminoalcohol). A mechanism, consistent with the observed kinetic data, is proposed.     

[{LiCH(CH2CH2OMen)SO2Ph}4] (OMen = Menthyl): Synthesis and First Structure of a Chiral Solvent Free Lithiated Sulfone with a Direct Li–C Bond

R*OCH₂CH₂CH₂SO₂Ph (R*OH = MenOH, (–)‐menthol, ( 3a ); BorOH, (1S)‐(–)‐borneol, ( 3b )) were found to react with n‐BuLi in n‐pentane/n‐hexane and toluene/n‐hexane under deprotonation yielding LiCH(CH₂CH₂OR*)SO₂Ph (R* = Men, ( 4a ); Bor, ( 4b )) which reacted with n‐Bu₃SnCl forming the requisite tri(n‐butyl)tin compounds n‐Bu₃SnCH(CH₂CH₂OR*)SO₂Ph (R* = Men, ( 5a ); Bor, ( 5b )) as diastereomeric mixtures. The identities of 5a and 5b were unambiguously proved by ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopic measurements. Solutions of 4a afforded crystals of [{LiCH(CH₂CH₂OMen)SO₂Ph}₄] ( 4a′ ) for which the structure was determined by single‐crystal X‐ray crystallography. Complex 4a′ crystallized in a tetrameric structure without any additional solvent molecules. There were found direct Li–C bonds (Li1–C1/Li2–C20 2.231(9)/2.236(9) Å). The tetrahedral donor set of Li is completed by three oxygen atoms. One oxygen atom comes from the OMen substituent via intramolecular coordination and two oxygen atoms come from SO₂ groups of neighboured LiCH(CH₂CH₂OMen)SO₂Ph moieties. Thus, a heterocubane structure with a Li₄S₄ core is built up.     

Ferromagnetic Interaction in μ1,3‐Cyanamido‐Derived Copper(II) Cryptates

The reaction of dinuclear copper(II ) cryptates with calcium cyanamide, CaNCN, and sodium dicyanamide, Na[N(CN)₂] results in dinuclear compounds of formulae [Cu₂(HNCN)(R3Bm)](ClO₄)₃ ( 1 ), [Cu₂(dca)(R3Bm)](ClO₄)₃?4H₂O ( 2 ), and [Cu₂(NCNCONH₂)(R3Bm)](CF₃SO₃)₃ ( 3 ), in which R3Bm=N[(CH₂)₂NHCH₂(C₆H₄‐m)CH₂NH(CH₂)₂]₃N and dca=dicyanamido ligand (NCNCN^?). The X‐ray diffraction analysis reveals for both 1 and 3 a dinuclear entity in which the copper atoms are bridged by means of the ‐NCN‐ unit. The molar magnetic susceptibility measurements of 1–3 in the 2–300 K range indicate ferromagnetic coupling. The calculated J values, by using theoretical methods based on density functional theory (DFT) are in excellent agreement with the experimental data. Catalytic hydration of a nitrile to an amide functional group is assumed responsible for the formation of 3 from a μ_1,3‐dicyanamido ligand.     

Mass spectra of some neopentylphosphorus derivatives

The fragmentation patterns and major metastable ions of the mass spectra of the neopentyl-phosphorus derivatives [(CH₃)₃CCH₂]₃P, [(CH₃)₃CCH₂]₂P(O)H, [(CH₃)₃CCH₂]_nPX_3-n (n = 1 and 2; X = H, Cl, C₆H₅ and CH = CH₂), [(CH₃)₃CCH₂]₃PS, [(CH₃)₃CCH₂]_nP(S)R_3-n (n = 1 and 2; R = C₆H₅ and CH = CH₂), [(CH₃)₃ CCH₂]₂PCH₂CH₂P[CH₂C(CH₃)₃]₂, ([CH₃)₃CCH₂]₂PCH₂PCH₂-CH₂P(H)C₆H₅ and [(CH₃)₃CCH₂]₂PCH₂CH₂P(S)(CH₃)₂ are described. Fragmentation of a neopentyl group by elimination of either C₄H₈ or CH₃ is very favourable when the neopentyl group is bonded to either a tricoordinate or tetracoordinate phosphorus atom. In neopentylphosphines with two or three neopentyl groups, stepwise elimination of C₄H₈ from all of the neopentyl groups occurs very readily. The resulting [(CH₃)_nPX]^+._3-n ions are often the most intense ions in the mass spectra.     

Lanthanide(II) Complexes of the Dihydrotriazinido Ligand [N{C(Ph)=N}2C(tBu)Ph]−

The potassium dihydrotriazinide K(L^Ph,tBu) ( 1 ) was obtained by a metal exchange route from [Li(L^Ph,tBu)(THF)₃] and KOtBu (L^Ph,tBu = [N{C(Ph)=N}₂C(tBu)Ph]). Reaction of 1 with 1 or 0.5 equivalents of SmI₂(thf)₂ yielded the monosubstituted Sm^II complex [Sm(L^Ph,tBu)I(THF)₄] ( 2 ) or the disubstituted [Sm(L^Ph,tBu)₂(THF)₂] ( 3 ), respectively. Attempted synthesis of a heteroleptic Sm^II amido‐alkyl complex by the reaction of 2 with KCH₂Ph produced compound 3 due to ligand redistribution. The Yb^II bis(dihydrotriazinide) [Yb(L^Ph,tBu)₂(THF)₂] ( 4 ) was isolated from the 1:1 reaction of YbI₂(THF)₂ and 1 . Molecular structures of the crystalline compounds 2 , 3· 2C₆H₆ and 4· PhMe were determined by X‐ray crystallography.     

Gold(I) and Palladium(II) Complexes Containing the Functionalized Ylides Triarylphosphonium Cyanomethylide or 2-Cyanoethylide (R3P=CHR′, R′=CN,CH2CN)

The coordination properties of ylides R₃P=CHCN and R₃P=CHCH₂CN were studied. Ylide R₃P=CHCN reacts with [AuCl(tht)] (molar ratio 1 : 1, tht=tetrahydrothiophene) to give [AuCl{CH(PPh₃)CN}] ( 1 ). Dinuclear complexes [(AuL)₂{μ-C(PR₃)CN}]ClO₄⋅nH₂O (n=1, L=PPh₃, R=Ph ( 2a ) or Tol (=4-MeC₆H₄) ( 2b ); n=0, R=Tol, L=P(pmp)₃ ( 2c ; pmp=4-MeOC₆H₄ or AsPh₃ ( 2d )) are the products of reactions between phosphonium salts (R₃PCH₂CN)ClO₄ (R=Ph or Tol) and [Au(acac)L] (molar ratio 1 : 3, L=PPh₃ or P(pmp)₃; acacH=acetylacetone). The reaction of [Au(acac)PPh₃] with (Ph₃PCH₂CH₂CN)ClO₄ (Au/P 2 – 5) gives the mononuclear complex [Au{CH(PPh₃)CH₂CN}(PPh₃)]ClO₄⋅0.5 H₂O ( 3 ). Complexes 2b or 2c react with [Au(acetone)L]ClO₄ (molar ratio 1 : 1, L=PPh₃ or P(pmp)₃), prepared in situ from [AuCl(L)] and AgClO₄ in acetone, to give the corresponding trinuclear derivatives [(AuL)₂{μ₃-{C(PTol₃)CN}(AuL)}](ClO₄)₂ (L=PPh₃ ( 4a ) or P(pmp)₃ ( 4b )]. We attempted unsuccessfully to prepare single crystals of 4a or 4b or of the triflate salt [{Au(PPh₃)}₂{μ₃-{C(PTol₃)CN}(AuPPh₃)}](TfO)₂⋅H₂O ( 4a′ ), obtained by reacting 4a with 2 equiv. of KCF₃SO₃. In complexes 2 and 4 , two new types of coordination of the ylides R₃P=CHCN are present. Attempts to coordinate three AuL groups to the N-atom of (R₃PCCN)⁻ induced by aurophilicity (see A and B ) were unsuccessful. The reaction between PdCl₂ and R₃P=CHCN (molar ratio 1 : 2) gives trans-[PdCl₂{CH(PTol₃)CN}₂] ( 5 ).     

Preparation of Dimethyl and Chloro/Methyl Complexes of Platinum(II) Supported by α‐Diimine Ligands: Trends in the Ease of Oxidation to Platinum(IV)

α‐Diimine ligands react with the platinum(II) alkyl complexes [(Me₂S)PtMe₂]₂ and (Me₂S)₂PtClMe to form (RDAB^R′)PtMe₂ and (RDAB^R′)PtClMe (RDAB^R′=RN=CR′−CR′=NR; R=2,6‐Me₂Ph, 2,6‐(CHMe₂)₂Ph, 3,5‐Me₂Ph, 3,5‐(CF₃)₂Ph, C₆H₁₁; R′=Me, H). The oxidation of these complexes with Cl₂, I₂, N‐chlorosuccinimide, [PtCl₆]²⁻ and (TMEDA)PtMe₂I₂ has been investigated. Attempts to determine the oxidation potentials of the Pt^II complexes electrochemically yielded only irreversible one‐electron oxidations. However, a qualitative ordering of increasing difficulty of oxidation has been determined for the series (RDAB^R′)PtMe₂<(RDAB^R′)PtClMe<(RDAB^R′)PtCl₂≪(RDAB^R′)PtMe(solvent)]⁺. The oxidation proceeds via a two‐electron inner‐sphere electron transfer from a bridged binuclear intermediate. The oxidation of (RDAB^R′)PtMe₂ by (TMEDA)PtMe₂I₂ exhibits characteristic third‐order kinetics, first‐order each in [Pt^II], [Pt^IV] and [I⁻]. Oxidation by a one‐electron process in MeCN solution results in a rapid subsequent disproportionation to Pt^IIMe and Pt^IVMe₃ cations with MeCN occupying the fourth or sixth coordination sites. Single‐crystal X‐ray structure determinations for [(2,6‐Me₂PhDAB^Me)PtMe₃(MeCN)]⁺[PtCl₆]_0.5(MeCN) and [(CyDAB^H)PtMe₃(MeCN)]⁺[PtCl₆]_0.5(MeCN) are reported.     

Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives,Dimethyl Sulphoxide and Chloride: Syntheses,Molecular Structures,and ESCA Data

The platinum(II) mixed ligand complexes [PtCl(L^1‐6)(dmso)] with six differently substituted thiourea derivatives HL, R₂NC(S)NHC(O)R′ (R = Et, R′ = p‐O₂N‐Ph: HL¹; R = Ph, R′ = p‐O₂N‐Ph: HL²; R = R′ = Ph: HL³; R = Et, R′ = o‐Cl‐Ph: HL⁴; R₂N = EtOC(O)N(CH₂CH₂)₂N, R′ = Ph: HL⁵) and Et₂NC(S)N=CNH‐1‐Naph (HL⁶), as well as the bis(benzoylthioureato‐κO, κS)‐platinum(II) complexes [Pt(L^{1, 2})₂] have been synthesized and characterized by elemental analysis, IR, FAB(+)‐MS, ¹H‐NMR, ¹³C‐NMR, as well as X‐ray structure analysis ([PtCl(L¹)(dmso)] and [PtCl(L^{3, 4})(dmso)]) and ESCA ([PtCl(L^{1, 2})(dmso)] and [Pt(L^{1, 2})₂]). The mixed ligand complexes [PtCl(L)(dmso)] have a nearly square‐planar coordination at the platinum atoms. After deprotonation, the thiourea derivatives coordinate bidentately via O and S, DMSO bonds monodentately to the Pt^II atom via S atom in a cis arrangement with respect to the thiocarbonyl sulphur atom. The Pt—S‐bonds to the DMSO are significant shorter than those to the thiocarbonyl‐S atom. In comparison with the unsubstituted case, electron withdrawing substituents at the phenyl group of the benzoyl moiety of the thioureate (p‐NO₂, o‐Cl) cause a significant elongation of the Pt—S(dmso)‐bond trans arranged to the benzoyl‐O—Pt‐bond. The ESCA data confirm the found coordination and bonding conditions. The Pt 4f_7/2 electron binding energies of the complexes [PtCl(L^{1, 2})(dmso)] are higher than those of the bis(benzoylthioureato)‐complexes [Pt(L^{1, 2})₂]. This may indicate a withdrawal of electron density from platinum(II) caused by the DMSO ligands.     

New water-soluble (hydroxymethyl)triphosphine [(HOCH2)2PCH2CH2]2PCH2OH, a derived PdII(triphosphine) complex, and triphosphine trioxide

An aqueous solution of (hydroxymethyl)triphosphine [(HOCH₂)₂P(CH₂)₂]₂PCH₂OH (II) was synthesized in situ by treatment of the triphosphine H₂P(CH₂)₂PH(CH₂)₂PH₂ with formaldehyde. Addition of a CH₂Cl₂ solution of trans-PdCl₂(PhCN)₂ to an in situ aqueous solution of II resulted in the formation of a species thought to be [PdCl{[(HOCH₂)₂P(CH₂)₂]₂PCH₂OH}]⁺Cl⁻. Attempts to isolate the complex were unsuccessful because of conversion to material containing small amounts of phosphine oxide(s) formed via a redox reaction involving water. The triphosphine trioxide [(HOCH₂)₂P(O)(CH₂)₂]₂P(O)CH₂OH was readily isolated from an in situ solution of II by treatment with aqueous H₂O₂.     

Bisisocyanide complexes of Zn(II) halides: Synthesis,structure, and application in the catalysis of isocyanides reaction with secondary amines

Isocyanide zinc complexes [ZnX₂(CNR)₂] (X = Cl, Br, I; R = Xyl, Cy, Bu^t) have been prepared via the interaction of the corresponding zinc halides ZnX₂ and isocyanide CNR in toluene at 100°C (yield 64–77%) and characterized by the data of elemental analysis, mass spectrometry, IR and NMR spectroscopy, and X-ray diffraction analysis. The zinc complexes [ZnBr₂(CNR)₂] (R = Xyl, Сy) have been used as catalysts for the synthesis of formamidines R¹N=CHNR₂ ² [R¹ = Xyl, Сy; R₂ ² = Et₂, (CH₂)₄, (CH₂CH₂)₂NMe, Me + CH₂Ph] from isocyanides CNR¹ and secondary amines HNR₂ ² in bulk (yield 92–98%).     

Cationic Palladium(II), Platinum(II), and Rhodium(I) Complexes as Acetalisation Catalysts

The use of [Pd(H₂O)2(Ph₂PCH₂CH₂PPh₂)] (CF₃SO₃)₂ as a catalyst for the acetalisation of a variety of aldehydes and ketones and for trans-acetalisation is described. It is also shown that Pt(H₂O)2(PH₂PCH₂CH₂PPh₂) (CF₃SO₃)₂ is at least as effective as the corresponding Pd compound, while much lower reaction rates are observed with [Rh(MeOH)₂(Ph₂PCH₂CH₂PPh₂)] [BF₄].     

Platinum group metal functionalized phosphine complexes. Part 2. Phosphinoamide rhodium(I), iridium(I), palladium(II) and platinum(II) complexes

Summary Rhodium(I), iridium(I), palladium(II) and platinum(II) complexes of the phosphinoamide ligands, Ph₂PCH₂CONHR (R = H, HDPA; Me, MDPA; Ph, PDPA) were prepared and characterized by using conductivity data, i.r., ¹H and ³¹P(H) n.m.r. spectral data. Reaction of the ligands with MCl(PPh₃)₃ and MCl(CO)(PPh₃)₂ (M = Rh, Ir) in CH₂Cl₂ under reflux lead to the formation of MCl(PPh₃)₂ [Ph₂PCH₂C(O)NHR] and MCl(CO)(PPh₃)[Ph₂PCH₂–C(O)HNR] respectively. The reaction of either K₂MCl₄ or cis-MCl₂(PPh₃)₂ affords complexes of the type cis-MCl₂[Ph₂PCH₂C(O)NHR]₂ (M = Pd, Pt). A similar product results even from the reaction of phosphinoamides with cis-platin. Possible structures are proposed for the complexes based on their physicochemical data