Xue-Lei Hu

Syntheses, weak interactions, and 3-D network structures of two salts based on [Ni(i-mnt)2]2− (i-mnt2−=iso-maleonitriled-ithiolate) anion with substituted pyridinium cation

Two new salts, [2-NaMePy]2[Ni(i-mnt)2] (1) and [2-NaMe-4-MePy]2[Ni(i-mnt)2] (2) ([2-NaMePy]+ = 1-(2′-naphthylmethyl)pyridinium, [2-NaMe-4-MePy]+ = 1-(2′-naphthylmethyl)-4-methylpyridinium and i-mnt2− = iso-maleonitriledithiolate), have been prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. The anions in 1 form a 1-D chain through short C ··· N interactions between the anions, while the cations in 2 stack a 1-D column via C–H ··· π and π ··· π stacking interactions between the cations. The effect of weak intramolecular interactions such as C–H ··· N, C–H ··· S, C–H ··· Ni hydrogen bonds, and π ··· π stacking interactions between the cations and the anions further generate a 3-D network structure. The change of the molecular topology of the countercation when the 4-substituted group in the pyridine ring is changed from H atom to CH3 group results in different crystal system, space group, and the stacking mode of the cations and anions of 1 and 2.

Synthesis and crystal structure of alkaline-earth metal cryptates of a ligand derived from 2,6-diformyl-pyridine

New alkaline-earth metal cryptates [ML](ClO4)2 · solvent (M = Ca2+, Sr2+, Ba2+; L = 1,4, 12,15,18,26,31,39,42,43,44-undecaazapentacyclo-[13.13.13.16,10.120,24.133,37]-tetratetraconta-4, 6, 8, 10(44), 11,18,20,22,24(43),25,31,33,35,37(42),38-pentadecaene) were synthesized by [2 + 3] template condensation of tris(2-aminoethyl)amine with 2,6-diformylpyridine and characterized by physical methods. The crystal structure of the calcium cryptate was determined. The central atom is nine coordinate with three pyridyl and six imino nitrogen atoms. The coordination polyhedron can be described as slightly distorted tricapped trigonal prism.

Syntheses, Crystal Structures, Weak Interactions, and Properties of Two Salts Containing Bis(maleonitriledithiolato)nickel/Palladium(II) Anion and Disubstituted Benzylpyridinium

Two new salts, [NO2BrBzPy]2[M(mnt)2] ([NO2BrBzPy]+= 1-(2′-bromo-4′-nitrobenzyl)pyridinium; mnt2−= maleonitriledithiolate; M = Ni(1), Pd(2)) have been prepared and characterized by elemental analyses, IR, UV, ESI-MS spectra, TG, and single-crystal X-ray diffraction. The results reveal that when the metal ion is changed from Ni(II) to Pd(II), the crystal system, and the dihedral angles between the phenyl and pyridine rings and the C-C-N reference plane of the cation, and the stacking modes of the anions and the cations are evidently different. Some weak interactions such as C–H···Br, C−H···O, C−H···N and C−H···S hydrogen bonds, p or stacking interactions in 1 and 2 play important roles in the molecular stacking and generate a 2D structure.

Synthesis, Complicated Weak Interactions, and Network Structure of a New Salt Containing Bis(iso-maleonitriledithiolato)nickel(II) Anion and Substituted Dipyridinium

A new salt, [EtdiPy][Ni(i-mnt)2](1) (i-mnt = iso-maleonitriledithiolate, [EtdiPy]2+= 1,1′-ethylene-2,2′-dipyridinium) has been synthesized and characterized by elemental analysis, IR, UV-Vis, EI-MS spectra, and single crystal X-ray diffraction. It is interesting that the [Ni(i-mnt)2]2− anions containing Ni(1) atom form a 1D chain by the π···π stacking interactions between the CN groups, while the anions containing Ni(2) atom form a ring structure through the S···N short interactions. The weak p···π and π···π stacking interactions, as well as C‒H···N and C‒H···S hydrogen bonds between the anions and the cations observed in the crystal, give further rise to a complicated network structure.