Molecular and Supramolecular Structures of 1‐Phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H₂L) and its Complexes with Diphenyllead(IV) Chloride and Acetate

Abstract

Reaction of 1-phenyl-4-phenylacetyl-2-thiosemicarbazide (H 2 L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh 2 Cl 2 (H 2 L) 2 ] and [PbPh 2 L]. The ligand and the complexes were characterized by elemental analyses, 1 H and 13 C NMR spectroscopy and X-ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H 2 L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh 2 Cl 2 (H 2 L) 2 ]·4MeOH has slightly distorted all-trans octahedral geometry around the lead atom, and the fact that the ligand is S-bound rather than O-bound suggests that PbPh 2 Cl 2 behaves as a "soft" Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules 2247 form a three-dimensional supramolecular structure. In [PbPh 2 L]·Me 2 CO, the L 2Ϫ anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H 2 L induce significant changes in its configuration and lengthen the C-S and C-O bonds, suggesting an evolution of the dianion towards a thiol-enol form.

Synthesis, structure and dielectric constant properties of a novel 1D coordination polymer[K(2-PTA)(H2O)]n

“…The structure of 1 was identified by satisfactory elemental analysis, IR and X-ray diffraction [11]. In the IR spectrum, strong peaks at 1467, 1389, 1341 cm À1 for 1 were assigned to the tetrazole group [13], and a strong absorption at 1631, 1570, 1421 cm À1 corresponds to the m(COO À ) vibration of the carboxyl [14].…”

The Chelating Behaviour of 3‐(4‐X‐Phenyl)‐2‐sulfanylpropenoic Acids with the PbII Ion – Relevance of the Lone Electron Pair in the Supramolecular Structures of the 2:1 Complexes

“…[24] The main distortion in this pseudo-trigonal-bipyramidal arrangement is associated with the bond angles O (11) As revealed previously, [23] these deviations from the canonical geometry could be due to the influence of the SALEP, which repels and compresses the bonding [73.51(12) and 71.23(11)°], [14] an anionic complex with a ligand similar to Cl-pspa 2- 2+ , although the former is a borderline Lewis acid. [25] The bond lengths and angles of the ligand change only marginally upon deprotonation and coordination. The main modification occurs in the length of the two carboxylate C-O bonds, which became more similar in the complex (Table 1).…”

Synthesis, structure and dielectric properties of the first 1D Ba-tetrazole complex [Ba(4-TPA)2(H2O)4·3.5(H2O)]n

“…The structure of 1 was identified by satisfactory elemental analysis, IR and X-ray diffraction [12]. In the IR spectrum, strong peaks at 1475, 1395, 1360 cm À1 for 1 were assigned to the tetrazole group [14], and a strong absorption at 1625, 1574, 1427 cm À1 were assigned to the m (COO À ) vibration of the carboxyl [15].…”

“…The structure of 1 was identified by satisfactory elemental analysis, IR and X-ray diffraction [12]. In the IR spectrum, strong peaks at 1475, 1395, 1360 cm À1 for 1 were assigned to the tetrazole group [14], and a strong absorption at 1625, 1574, 1427 cm À1 were assigned to the m (COO À ) vibration of the carboxyl [15].Single crystal X-ray analysis reveals that complex 1 crystallized in the monoclinic group C2/c. The asymmetrical unit consists of one Ba(II) ion, two 4-TPA anions, four coordinated water molecules and three and a half uncoordinated water molecules.…”