ISONITRILE COMPLEXES OF VANADIUM(II)

Reaction between [Et(4)N][V(CO)(6)], halogen and isonitrile in tetrahydrofuran (THF) yielded the complexes VX(2)(CNR)(4) (X = Br; R = (t)Bu (1) or Cy (2)) (X = I; R = (t)Bu (3) or Cy (4)). [V(CO)(6)](-), I-2 and CN(t)Bu, when reacted in CH2Cl2, form [VI(CN(t)Bu)(5)]I (5). Replacement of Br-2 by pyridinium bromide leads to the formation of VBr2(py)(4) (6). The X-ray structures of 1, 3 and 5 are reported. Crystal data are as follows. For VBr2(CN(t)Bu)(4) . 2THF (1 . 2THF): monoclinic; P2(1)/n; a = 9.775(5) Angstrom, b = 10.160(5) Angstrom and c = 18.43(2) Angstrom; beta = 104.93 degrees; Z = 2; R(1) = 0.0693 and wR(2) = 0.1445. For VI2(CN(t)Bu)(4)(. 2THF (3 . 2THF): monoclinic; P2(1)/n; a = 9.86.0(2) Angstrom, b = 10.329(2) Angstrom and c = 18.686(4) Angstrom; beta = 104.39(3)degrees; Z = 2; R(1) = 0.0479 and wR(2) = 0.0982. For [IV(CN(t)Bu)(5)]I (5): orthorhombic; Pnma; a = 20.259(6) Angstrom, b = 11.503(2) Angstrom and c = 19.325(10) Angstrom; Z = 4; R(1) = 0.0793 and wR(2) = 0.1699.