Spectral characterization and crystal structure of tetrahydropyran-4-one thiosemicarbazones

Crystal structure and Hirshfeld surface analysis of rac-2-[2-(4-chloro-phen-yl)-3,4-di-hydro-2H-1-benzo-pyran-4-yl-idene]hydrazine-1-carbo-thio-amide

In the title compound, C16H14N3OSCl, a Schiff base derivative of a thio-semicarbazide with a flavanone, the 4-chlorophenyl ring is inclined to the benzene ring of the chromane ring system by 30.72 (12)°. The pyran ring has an envelope conformation with the methine C atom as the flap. The mean plane of the thio-urea unit is twisted with respect to the benzene ring of the chromanone ring system, subtending a dihedral angle of 19.78 (19)°. In the crystal, mol-ecules are linked by two pairs of N-H⋯S hydrogen bonds, forming inversion dimers enclosing R 2 2(8) ring motifs, which are linked to form ribbons propagating along the b-axis direction. The inter-molecular contacts in the crystal have been analysed using Hirshfeld surface analysis.

Bis(N'-{(E)-[(2E)-1,3-di-phenyl-prop-2-en-1-yl-idene]amino}-N-ethyl-carbamimido-thio-ato-κ2N',S)zinc(II): crystal structure and Hirshfeld surface analysis

The title ZnII complex, [Zn(C18H18N3S)2], (I), features two independent but chemically equivalent mol-ecules in the asymmetric unit. In each, the thio-semicarbazonate monoanion coordinates the ZnII atom via the thiol-ate-S and imine-N atoms, with the resulting N2S2 donor set defining a distorted tetra-hedral geometry. The five-membered ZnSCN2 chelate rings adopt distinct conformations in each independent mol-ecule, i.e. one ring is almost planar while the other is twisted about the Zn-S bond. In the crystal, the two mol-ecules comprising the asymmetric unit are linked by amine-N-H⋯N(imine) and amine-N-H⋯S(thiol-ate) hydrogen bonds via an eight-membered heterosynthon, {⋯HNCN⋯HNCS}. The dimeric aggregates are further consolidated by benzene-C-H⋯S(thiol-ate) inter-actions and are linked into a zigzag supra-molecular chain along the c axis via amine-N-H⋯S(thiol-ate) hydrogen bonds. The chains are connected into a three-dimensional architecture via phenyl-C-H⋯π(phen-yl) and π-π inter-actions, the latter occurring between chelate and phenyl rings [inter-centroid separation = 3.6873 (11) Å]. The analysis of the Hirshfeld surfaces calculated for (I) emphasizes the different inter-actions formed by the independent mol-ecules in the crystal and the impact of the π-π inter-actions between chelate and phenyl rings.