Bis{N′-[3-(4-nitrophenyl)-1-phenylprop-2-en-1-ylidene]-N-phenylcarbamimidothioato}zinc(II): crystal structure, Hirshfeld surface analysis and computational study

The title zinc bis(thiosemicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetrahedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethylene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitrobenzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitrobenzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supramolecular chain along the b-axis direction features amine-N—H...O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C—H...O(nitro) and π(chelate ring)–π(phenyl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C—H...O(nitro) and nitro-O...π(phenyl) interactions.

Induction of Λ-helicity in a zinc complex with an alanine-appended aminopyridine ligand

The crystal structure of tris[dimethyl 5-({1-[(pyridin-2-yl-κN)carbamoyl-κO]ethyl}carbamoyl)benzene-1,3-dicarboxylate]zinc(II) dinitrate acetonitrile trisolvate, [Zn(C19H19N3O6)3](NO3)2·3CH3CN or [Zn(L)3](NO3)2·3CH3CN, (1), has been determined by single-crystal X-ray diffraction. The neutral ligand L coordinates to the Zn2+ cation in a bidentate fashion via the pyridine N atom and an amide O atom, forming a six-membered chelate ring. The Λ-helical chirality of the Zn2+ coordination sphere is induced by pendant L-alanine residues through stacking interactions between the arene groups of two coordinated ligands, assisted by a hydrogen bond between amide groups bonded to the stacked arene rings. The third ligand is coordinated to the Zn2+ cation by the same six-membered chelate ring, but in the opposite direction with respect to the analogous chelate rings of the first two coordinated ligands. Besides ionic interactions between [ZnL 3]2+ complexes and NO3 − anions, several types of hydrogen bonds and intermolecular stacking interactions contribute to the stability of the solid-state phase.

Higher MLCT lifetime of carbene iron(ii) complexes by chelate ring expansion

High octahedricity and rigidity enable the high 9.2 ps 3MLCT lifetime of the iron(ii) complex [Fe(dpmi)2]2+ possessing only two carbene donor sites.

Supramolecular architectures sustained by delocalised C–I⋯π(arene) interactions in molecular crystals and the propensity of their formation

A survey of delocalised C–I⋯π(chelate ring) interactions is presented.

Experimental and computational evidence for a stabilising C–Cl(lone-pair)⋯π(chelate-ring) interaction

Stabilising C–Cl(lone-pair)⋯π(chelate ring) interactions are described.

Crystal and molecular structures of dichloridopalladium(II) containing 2-methyl- or 2-phenyl-8-(diphenyphosphanyl)quinoline

The crystal structures of dichloridopalladium(II) complexes bearing 2-methyl- and 2-phenyl-8-(diphenylphosphanyl)quinoline, namely, dichlorido[8-(diphenylphosphanyl)-2-methylquinoline-κ2 N,P]palladium(II), [PdCl2(C22H18NP)] (1) and dichlorido[8-(diphenylphosphanyl)-2-phenylquinoline-κ2 N,P]palladium(II), [PdCl2(C27H20NP)] (2), were analyzed and compared to that of the 8-(diphenylphosphanyl)quinoline (PQH) analogue (3). In all three complexes, the phosphanylquinoline moiety acts as a bidentate P,N-donating chelate ligand. In the PQH complex (3), the PdII center has a typical planar coordination environment; however, both the methyl- and phenyl-substituted phosphanylquinoline (PQMe and PQPh, respectively) complexes (1) and (2) exhibit a considerable tetrahedral distortion around the PdII center, as parameterized by the τ4 values of 0.1555 (4) and 0.1438 (4) for (1) and (2), respectively. The steric interaction from the substituted group introduced at the 2-position of the quinoline ring enforces the cis-positioned Cl ligand to be displaced from the ideal coordination plane. Also, the ideally planar phosphanylquinoline five-membered chelate ring shows a large bending deformation by the displacement of the PdII center from the quinoline plane. In addition, in the phenyl-substituted complex (3), the coordinating quinolyl and the substituted phenyl rings are not co-planar to each other, having a dihedral angle of 33.08 (7)°. This twist conformation prohibits any intermolecular π–π stacking interaction between the quinoline planes, which is observed in the crystals of complexes (1) and (2).