Copper(I) derivatives of 4-benzoylpyridine thiosemicarbazone and 3-formylpyridine-N-methylthiosemicarbazone with triphenylphosphine as a co-ligand

The manuscript describes, synthesis and crystal structures of 4-benzoylpyridine-thiosemcarbazone (1; abbrev. 4-bpytscH-NH2), and its copper derivative, namely, [CuCl(4-bpytscH-NH2)(PPh3)2] (2), as well as, analytical and spectral properties of 3-formylpyridine-N-methylthiosemicarbazone (3; 3-pytscH-NHMe), and crystal structure of [CuCl(3-pytscH-NHMe)(PPh3)2] (4). Crystal data: 1, monoclinic, P21/c, a ​= ​9.6128(8), b ​= ​14.9659(9), c ​= ​10.1568(6) Å; β ​= ​115.075(9), R factor ​= ​0.0403; 2: triclinic, P-1, a ​= ​10.3758(3), b ​= ​14.5607(5), c ​= ​17.5413(5) Å, α ​= ​65.569(3), β ​= ​79.767(3), γ ​= ​72.458(3), R factor ​= ​0.0410; 4: triclinic, P-1, a ​= ​9.6845(6), b ​= ​12.6211(5), c ​= ​18.1748(7) Å, α ​= ​99.757(3), β ​= ​98.651(4), γ ​= ​108.652(5), R factor ​= ​0.0405. The thio-ligand, as a neutral entity, is coordinating to Cu through its S donor atom in complexes 2 and 4. The geometry of each of complexes (2, 4) is distorted tetrahedral. The infrared, electronic absorption and proton NMR spectroscopic studies, are also reported. Compound 2 represents the first example of a structurally characterized copper coordination compound of a 4-pyridyl based thiosemicarbazone.