Trinuclear Gold(I) Complexes with Various Coordination Modes of N,N-dimethyldithiocarbamate

The compounds [Au₃(S₂CNMe₂)₃{ ₃-(PPh₂)₃CH]} (1) and [Au₃(S₂CNMe₂)(-S₂CNMe₂){ ₃-(PPh₂)₃CH}]ClO₄ (2) are obtained by reaction of [Au₃Cl₃{ ₃-(PPh₂)₃CH}] with three equivalents of sodium dimethyldithiocarbamate or two equivalents of the same reagent in the presence of excess NaClO₄. Reaction of 2 with the group 11 metal complexes [AuCl(tht)], CuCl or [Au(C₆F₅)(tht)] takes place with displacement of [M(S₂CNMe₂)]_n (M=Cu, Au) and formation of the new complexes [Au₃X(-S₂CNMe₂){ ₃-(PPh₂)₃CH}]ClO₄ (X=Cl (3), X=C₆F₅ (4)); further reaction of 3 with [Ag(OClO₃)(tht)] (tht=tetrahydrothiophene) affords the dicationic species [Au₃(-S₂CNMe₂){ ₃-(PPh₂)₃CH}(tht)](ClO₄)₂ (5). Treatment of [Au₃Cl₃{ ₃-(PPh₂)₃CH}] with one equivalent of NaS₂CNMe₂ allows the substitution of only one chlorine atom, giving rise to the complex [Au₃Cl₂(S₂CNMe₂){ ₃-(PPh₂)₃CH}] (6), in which the dithiocarbamate ligand acts as monodentate rather than bidentate bridging as observed in compounds 3–5. The crystal structures of complexes 1 and 2 have been established by X-ray diffraction studies and show close gold–gold contacts.     

Structural versatility of 5-methyltetrazolato complexes of (eta5-pentamethylcyclopentadienyl)iridium(III) incorporating 2,2'-bipyridine, N,N-dimethyldithiocarbamate, or 2-pyridinethiolate ligands

Several new mono- and dinuclear eta (5)-pentamethylcyclopentadienyl (Cp*) iridium(III) complexes bearing 5-methyltetrazolate (MeCN 4 (-)) have been synthesized and their molecular and crystal structures have been determined. For complexes incorporating 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen), both mononuclear kappa N (2)-coordinated and dinuclear mu-kappa N (1):kappa N (3)-bridging MeCN 4 complexes were obtained: [Cp*Ir(bpy or phen)(MeCN 4-kappa N (2))]PF 6 ( 1 or 3) and [{Cp*Ir(bpy or phen)} 2(mu-MeCN 4-kappa N (1):kappa N (3))](PF 6) 3 ( 2 or 4), respectively. It was confirmed by X-ray analysis that the dinuclear complex in 2 has a characteristic structure with a pyramidal pocket constructed from a mu-kappa N (1):kappa N (3)-bridging MeCN 4 (-) and two bpy ligands. In the case of analogous complexes with N, N-dimethyldithiocarbamate (Me 2dtc (-)), yellow platelet crystals of mononuclear kappa N (1)-coordinated complex, [Cp*Ir(Me 2dtc)(MeCN 4-kappa N (1))].HN 4CMe ( 5.HN 4CMe), and yellow prismatic crystals of dinuclear mu-kappa N (1):kappa N (4)-bridging one, [{Cp*Ir(Me 2dtc)} 2(mu-MeCN 4-kappa N (1):kappa N (4))]PF 6 ( 6), were deposited. The kappa N (1)- and kappa N (1):kappa N (4)-bonding modes of MeCN 4 (-) in these complexes presumably arise from the compactness of the Me 2dtc (-) coligand. 6 is the first example in which tetrazolates act as a mu-kappa N (1):kappa N (4)-bridging ligand. Furthermore, the molecular and crystal structures of dinuclear complexes having mu-kappa (2) S, N:kappa S-bridging 2-pyridinethiolate (2-Spy (-)) or 8-quinolinethiolate (8-Sqn (-)) ligands have been determined: [(Cp*Ir) 2(mu-2-Spy or 8-Sqn-kappa (2) S, N:kappa S) 2] ( 7 or 8). These thiolato-bridging complexes were stable toward the addition of 5-methyltetrazole (HN 4CMe), owing to the characteristic intramolecular stacking interaction between the pyridine or the quinoline rings. The 2-Spy complex of 7, however, reacted with an excess amount of Na(N 4CMe), resulting in cleavage of the IrN(py) bond and coordination of MeCN 4 (-) in the mu-kappa N (2):kappa N (3)-bridging mode: [(Cp*Ir) 2(mu-2-Spy-kappa S:kappa S) 2(mu-MeCN 4-kappa N (2):kappa N (3))]PF 6 ( 9). This bridging mode of MeCN 4 (-) was also observed in the triply bridging MeCN 4 complex: [(Cp*Ir) 2(mu-MeCN 4-kappa N (2):kappa N (3)) 3]PF 6 ( 10). In these various MeCN 4 complexes, the structural parameters of the MeCN 4 moiety were not perturbed by the difference in the bonding modes.     

The reaction of chloroalkyl(vinyl)silanes with N,N-dichloro sulfonamides

1. Download : Download high-res image (32KB)
2. Download : Download full-size image

     

Vibrational spectra and force constants ofS-methyl-N,N-dimethyldithiocarbamate

The IR and Raman spectra ofS-methyl-N,N-dimethyldithiocarbamate were studied in different phase states. The frequencies and vibration modes of normal vibrations were analyzed, and the erroneous assignments made in some previous works were corrected. The force constants of the molecule were estimated using the model of the generalized valenceforce field.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1108–1110, June, 1995.This work was carried out with partial financial support from the International Science Foundation.     

Electrochemical Oxidation of Bis(methylthio)benzenes

The bis(methylthio)benzenes 3a – 3c are oxidized to the methylsulfinyl-methylthiobenzenes 4a – 4c on a Pt-anode in good yields.     

Reactions of polyhalogenopyridines. 13. Reaction of isomeric tetrafluorocyanopyridines and pentafluoropyridine with sodium N,N-dimethyldithiocarbamate

The reactions of isomeric tetrafluoropyridines and pentafluoropyridine with sodium N,N-dimethyldithiocarbamate were studied. Substantial differences were found between the nature of their chemical transformations and those of the chlorine analogs. It was shown that tetrafluorocyanopyridines do not undergo heterocyclization with sodium N,N-dimethyldithiocarbarnate to form derivatives of 1,3-dithiolo[4,5-c]pyridine. Instead, extrusion of the CS₂ molecule from the N,N-dimethyldithiocarbanuue substituent at position 2 of the pyridine ring occurs.For communication 12, see [1].Chernogolovka Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka. Translated from Khimiya Geterotsklicheskikh Soedinenii, No. 8, pp. 1088–1093, August, 1996. Original article submitted June 20, 1996.     

Bis(methylthio)tetracenes: synthesis, crystal-packing structures, and OFET properties

5,12-Bis(methylthio)tetracene (2) and 5,11-bis(methylthio)tetracene (3) were synthesized. DFT calculations indicate that the HOMO and LUMO energy levels of 2 and 3 are lowered by 0.13-0.24 eV and their HOMO-LUMO energy gaps are reduced by 0.1 eV relative to those of tetracene. X-ray crystallographic data revealed that 2 is arranged as a result of a 1-D slipped-cofacial π-stacking with S-S and S-π interactions, similar to the packing arrangement of 6,13-bis(methylthio)pentacene (1), whereas 3 exhibits a herringbone packing arrangement without S-S interactions. The OFET devices fabricated using spin-coated films of soluble 1 and 2, with a bottom-contact device configuration, exhibited hole mobilities as high as 1.3 × 10(-2) and 4.0 × 10(-2) cm(2) V(-1) s(-1) with current on/off ratios of over 10(5) and 10(4), respectively.     

Reactive intermediates in the reaction of hydrazinecarbothioamides with 2-(bis(methylthio)methylene)malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate

Research on Chemical Intermediates - The reaction of N-substituted hydrazinecarbothioamides with both 2-(bis(methylthio)methylene)malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate...