C4H3SSeCH2CH2OC6H5: synthesis, characterization and reaction with palladium(II) and nickel(II)

ThSeCH2CH2OPh (Th=2-thienyl, C4H3S-; Ph=phenyl) (2) has been prepared by the reaction of BrCH2CH2OPh (1) and ThSeLi. The compound was characterized by 13C{1H}- and 77Se-NMR spectroscopy and X-ray crystallography. 2 is monoclinic, space group P21/c, a=10.865(2), b=5.152(1), c=41.996(8) Å, β=92.20(3)°. All bond lengths and angles are quite normal as exemplified by the respective SeC(alkyl) and SeC(aryl) bonds of 1.957(6)–1.966(6) and 1.901(7)–1.905(7) Å. The lattice is composed of discrete molecules that are joined together by weak hydrogen bonds into a three-dimensional network. Upon treating ThSeCH2CH2OPh with [PdCl2(NCPh)2] and [NiCl2(PPh3)2] in benzene, a dinuclear palladium complex [Pd2Cl2(μ-Cl)(μ-SeTh)(PPh3)2] (3) and a mononuclear complex [PdCl2(PPh3)2] (4) were formed together with a precipitation of NiCl2. The X-ray quality crystals were recrystallized in CH2Cl2. 3·2.5CH2Cl2 is monoclinic, space group C2/c, a=32.907(7), b=14.545(3), c=22.433(5) Å, β=114.37(3)° and contains a novel asymmetrical arrangement of one bridging chlorido and thienylselenolato ligand. Both palladium atoms show an square-planar coordination. The terminal PdCl bond lengths are 2.388(1) and 2.346(1) Å with slightly longer distances of 2.418(1) and 2.450(1) Å involving the bridging chlorido ligand. The PdSe distances are 2.4092(9) and 2.4376(7) Å.