Udo Kunze

Das verhalten von tetraorganozinn-verbindungen gegenüber flüssigem schwefeldioxid

Abstract In contrast to (n-C4H9)4Sn and (C6H5)4Sn, (CH3)4Sn and (C2H5)4Sn absorb one mole of SO2 at −20° to yield the corresponding penta-coordinate, colourless, stable trialkyltin alkanesulfinates, R3SnO2SR (R = CH3, C2H5). While (CH3)4Sn at 60° reacts with liquid SO2 to give in high yields bis(trimethyltin) sulfate, [(CH3)3Sn]2SO4, a mixture of hexa-coordinate diethyltin bis(ethanesulfinate) and bis(triethyltin) sulfate was obtained from (C2H5)4Sn and SO2. On the basis of infrared, Raman, 1H NMR, Mossbauer, and mass spectroscopic investigations, all the compounds described here are double O-sulfinato and sulfato complexes respectively.

Über ψ-tetra-, penta- und hexakoordinierte sulfinatokomplexe des zinns

Abstract Colourless, stable, polymeric, ψ-tetrahedrally coordinated O -sulfinates of divalent tin, Sn(O 2 SR) 2 , were obtained by reaction of SNCl 2 ·2 H 2 O with sodium organosulfinates, NaO 2 SR (R = p -CH 3 C 6 H 4 , C 6 H 5 ), in ethanol. Colourless penta- and hexa-coordinated double O -sulfinato complexes of the type (C 6 H 5 ) 3 SnO 2 SR, (C 6 H 5 ) 2 Sn(O 2 SR) 2 and (CH 3 ) 2 Sn(O 2 SR) 2 were formed respectively by reaction of triphenyltin chloride and diphenyl- and dimethyltin dichloride with sodium organosulfinates, NaO 2 SR (R = p -CH 3 C 6 H 4 , C 6 H 5 , CH 3 ), in THF. The structural investigations were performed with the aid of infrared, Raman, Mossbauer, and mass spectroscopy.

55Mn NMR characteristics of carbonylmanganese complexes with hetero-substituted dithioformato-, thioformamido- and thioformamide ligands [1]

Abstract Complexes wth the general formulae [(CO)4MnS2CZ] (Z = OR, SR, NR2, PR2, P(S)R2, AsPh2, Ph), [(CO)4 MnSC(NR′)P R2], [(CO)4 MnSC(NR′)P(S) R2] and fac-[(CO)3Br MnSC(NHR′)P R2] exhibit 55Mn chemical shift ranges which allow classification with respect to the mode of coordination of the thio ligand and the ring size of the chelate structure. Shielding decreases, in the series chelate-4 ring (S,P-coordinated) > chelate-5 ring (S,S′) > chelate-4 ring (S,S′). Within the group of [(CO)4MnS2CZ] complexes, shielding decreases in the order NR2 > OR > Ph > AsPh2 > P(S)R2 > SR. The trends are explained in terms of varying contributions of molecular parameters to the paramagnetic term of the shielding constant, and related to structure data. There is no apparent correlation between line widths of the 55Mn resonance signals and molecular parameters.

Über tri- und tetrasulfinato-komplexe des zinns

Abstract Hitherto unknown tri- and tetrasulfinato complexes of tin are obtained according to equations (1) and (2) by treating organotin trichlorides, RSnCl3 (R = CH3C6H5) and SnCl4 with sodium organosulfinatees, NaO2SR’ (R’ = C6H5p-CH3C6H4). Especially, the trisulfinates prove to be monomeric in CHCl3. The possible structure models of all compounds are discussed on the basis of their IR, 1H NMR, and Mossbauer spectra.

Phosphinsubstituierte Chelatliganden, IV [1] Neue Diphenylphosphinoformamid-Komplexe des Mangans und Eisens / Phosphine Substituted Chelate Ligands, IV [1] New Diphenylphosphino Formamide Complexes of Manganese and Iron

The phosphino and (thio)phosphoryl formamides 1a, b, 2a-c, 3a, b, 4a, b which were partially unknown are synthesized by various methods, and their reactions with carbonylmetal halides of manganese and iron are described. The formation of the P,N- and S,N coordinate chelate complexes, (CO)4MnL (5 a, 8a), is limited to the N-phenyl derivatives la and 4a. With L = 2a, b, the unidentate P-coordination predominates. Thus, the carbonylmetal halide complexes cis-(CO)4Mn(X)L (6a, b: X = CI, 7a, b: X = Br) and η5-C5H5(CO)Fe(X)L (9a, b: X = I, 10a, b: X = Br) are obtained. Due to the low stability of the formamide complexes, their formation is always accompanied by isocyanate elimination as a side-reaction

Phosphinsubstituierte Chelatliganden, IX [1]. NMR-Spektren und Kristallstruktur von Diphenyl(thio)phosphoryl-N,N-dimethylthioformamid / Phosphine Substituted Chelate Ligands, IX [1]. NMR Spectra and Crystal Structure of Diphenyl(thio)phosphoryl-N,N-dimethylthioformamide

The P=S and P=0 derivatives 2a, b of diphenylphosphino N,N-dimethylthioformamide (1) were obtained by addition of sulfur to 1 and by Arbusov reaction of Ph2POMe with Me2NC(S)Cl, respectively. The position of the cis-P N-methyl proton signal is markedly affected by the P = X group which exerts a diamagnetic shift for X = S (2a) but a paramagnetic shift for X = O (2b) relative to 1. Unusually small 3JPC couplings are observed in the 13C{1H} NMR spectrum. The P-sulfide 2 a crystallizes in the monoclinic space group C2/c with the lattice constants a = 1791.5(3) pm, b = 686.7(2) pm, c = 2591.3(4) pm, β = 93.10(4)°. The molecule structure is characterized by a planar thioamide unit with the P=S group forming an angle of 53.4° to the plane.

Notizen: Synthesis of Trialkylstannanedithi ocarboxy lato Rhenium(I) Complexes [1]

Abstract Novel trialkylstannanedithiocarboxylato complexes are formed in a one-pot reaction of R3SnCS2Li (R = benzyl, methyl, cyclohexyl) with BrM(CO)5 (M = Mn, Re) in a THF/dioxane solution. Tetracarbonylmetal species could be detected by IR spectroscopy in all cases. The more stable rhenium chelate complexes, R3SnCS2Re(CO)4, were isolated by chromatographic separation as yellow, low-melting solids with 10-20% yield.

Phosphinsubstituierte Chelatliganden, VI [1]. Kristallstrukturen von Tetracarbonyl(diphenylphosphino -N-phenylthioformimidato -P,S )mangan(I) und Tetracarbonyl(diphenylthiophosphoryl-N-phenylthioformimidato-S,S')mangan(I) / Phosphine Substituted Chelate Ligands, VI [1]. Crystal Structures of Tetracarbonyl(diphenylphosphino-N-phenylthioformimidato-P,S)- manganese(I) and Tetracarbonyl(diphenylthiophosphoryl-X-phenylthioformimidato-S.S')- manganese(I)

Abstract The phosphinothioformimidato complex (1) crystallizes triclinic in the space group P1̄ with lattice constants a = 989.4(9) pm, b - 1042.0(8) pm, c = 1088.5(8) pm, α = 91.45(4)°, β = 97.10(4)°, γ = 100.53(5)°. The four-membered chelate ring is folded over the P-S edge by a dihedral angle of 167.1°. The crystal system of the thiophosphoryl thioformimidato complex (2) is monoclinic with the space group P21/c, and the lattice parameters are a = 1109.5(3) pm, b = 966.0(3) pm, c = 2256.7(3) pm, β=103.11(2)°. The chelate ligand is linked to the metal by two S atoms forming a five-membered ring in the “envelope” conformation with the thiophosphoryl S atom at the apical position.

Reaktivität metallorganischer Komplexe mit Zinn-Metall-Bindung, IV [1]. SO2 -Insertion an phosphinsubstituierten und anionischen Triorganozinn-Komplexen des Chroms, Molybdäns und Wolframs / Reactivity of Organometallic Complexes Containing Tin-Metal Bonds, IV [1]. SO2 Insertion into Phosphine Substituted and Anionic Triorganotin Complexes of Chromium, Molybdenum and Tungsten

Abstract The trans phosphane and phosphite substituted organotin complexes of molybdenum 1-4 are prepared by thermolysis or photolysis of the tricarbonyl parent compounds. The phosphane complexes 1 and 2 react readily with liquid sulfur dioxide by absorption of 1-3 moles of SO2 depending on temperature. IR and NMR spectra indicate cleavage of tin-carbon bonds only yielding insertion products of the sulfinato-O type 1a-c and 2a-c. The phosphite complexes 3, 4 are less reactive and yield a di-insertion 3a and a mono-insertion compound 4a. The anionic triphenyltin derivatives of chromium, molybdenum and tungsten 5-7 undergo facile cleavage of 1 (Cr) or 3 (Mo, W) tin-phenyl bonds. The course of SO2 insertion into 1-7 reveals a distinct activation of the Sn-C bond in organotin transition metal complexes by substitution with stronger donor molecules or reduction to anionic species.

Phosphinsubstituierte Chelatliganden, XXV [1] Diastereoselektive Komplexierung chiraler Phosphinothioformamide mit entferntem Asymmetriezentrum

Abstract For further studies of the diastereoselective complex formation of ambidentate chiral chelating ligands, we prepared the racemic phosphinothioformamides. Ph2P(X )C(S)NHC*HR 1R2, with X = 2e- (R1 = Ph,R2 = Et: 1a;R1 = Ph,R2 = iPr:2a; R2 = Me,R2 = Et:3a) and X = O (1b ,2b ) according to a previously reported route. The coordination of 1a -3a to CpM (CO)3Cl (M = Mo, W) in m ethanol gives the diastereomeric P.S-chelate complexes, (Mo: 4-6, W: 7-9). In solution, epimerisation proceeds to an equilibrium ratio of B/A = 1,5 in case of 4, 5, 7, and 8, but less than 1,1 with 6 and 9. A reduced diastereoselectivity (d.e. 10 -20%) is also observed during the formation of the analogous molybdenum complexes 10a-d with phosphine ligands derived from α-amino acid esters. Ph2PC(S)NHC*H(R)COOMe [R = Me (L-Ala), CH2Ph (L-Phe). CHMe2 (L-Val). Ph (D-phenylglycine)]. The results indicate a significant asymmetric induction despite of the four bond distance of the chiral centres.