The influence of the substituents at N1 nitrogen on geometry of nickel(II) complexes with heterocyclic thiosemicarbazones

The influence of the substituents (R) at the N1 nitrogen of heterocyclic thiosemicarbazones {(C4H3X)–C(H)double bond; length as m-dashN3–N2H–C1(double bond; length as m-dashS)N1HR; X = O, Hftsc; S, Httsc} on the geometry of nickel(II) complexes was investigated. Furan-2-carbaldehyde thiosemicarbazones have formed both trans [Ni(ftsc-N-R)2] (R = Me, 1; Et, 2), and cis (R = Ph, 3), square planar complexes unlike thiophene-2-carbaldehyde thiosemicarbazones which yielded only trans square planar complexes [Ni(ttsc-N-R)2] (R = Me, 4; Et, 5; Ph, 6).