SYNTHESIS AND CRYSTAL STRUCTURE OF A TRINUCLEAR NICKEL(II) ONO PINCER COMPLEX [Ni(Pydc)2]2[Ni(H2O)5]?2H2O?2(C6H15N)

trinuclear Ni(II) pincer complex 2 6-pyridinedicarboxylic acid crystal structure.

"ПРАВИЛЬНЫЕ" И "НЕПРАВИЛЬНЫЕ" ВОДОРОДНЫЕ СВЯЗИ В ЖИДКОЙ ВОДЕ, КРИСТАЛЛИЧЕСКАЯ СТРУКТУРА НОВОГО КОМПЛЕКСА бис(4,4,10,10-ТЕТРАМЕТИЛ-1,3,7,9-ТЕТРААЗОСПИРО[5.5]УНДЕКАН-2,8-ДИОН-O)- ДИАКВА-трис(НИТРАТО-О,О')-ЛАНТАНА, ...

Both terminal Ni(II) centers are coordinated to two ONO pincer ligands (pydc) bridged by the nickel penta aqua unit. <...> INTRODUCTION In recent decades, two new branches of coordination chemistry emerged significantly are metalorganic frameworks (MOFs) and supramolecular coordination complexes (SCCs). <...> The former is comprised of infinite networks of metal centers or inorganic clusters bridged by simple organic linkers through metal-ligand coordination bonds. <...> The latter encompasses discrete systems in which carefully selected metal centers undergo self-assembly with ligands containing multiple binding sites oriented with specific angularity to generate a finite supramolecular complex. <...> Supramolecular frameworks can be constructed through two different interactions: (i) coordinate covalent bonds and (ii) noncovalent intermolecular forces such as hydrogen bonding, — stacking, and Coulomb interactions. <...> Seldom, pincer complexes were also categorized under SCCs and that, too, after the first demonstration of pincer type ligands by Moulton and Shaw in 1976 [ 1, 2 ] Especially in Ni mediated pincer complexes, the arrangement of atoms in the pincer ligand coordinating to the metal is in the meridional fashion, thus the coordination is similar to the arrangement of atoms in supramolecular coordination complexes. <...> More importantly, weaker noncovalent interactions (especially hydrogen bonds) associated with Ni-based pincer complexes, played a crucial role in fundamental biological processes, such as the expression and transfer of genetic information. <...> Hence, it is paramount important to develop nickel-based pincer complex systems with weaker noncovalent interactions. <...> Nickel acetate, 2,6-pyridinedicarboxylic acid (Alfa Aesar), and triethylamine (Merck) were used as received. <...> The FT-IR spectra were recorded as KBr pellets in the range 4000—400 cm–1 on a Thermo Scientific–Nicolet iS5 spectrophotometer. <...> Triethylamine was added dropwise until it raised the solution pH to 8.0. <...> Data were collected at 110 K from a Cu sealed X-ray tube (Kh = 1.5418 Е with a potential of 40 kV and a current of 40 mA) fitted with a graphite monochromator in the parallel mode (175 mm collimator with 0.5 mm pinholes). <...> Volume, Е3 Z Density (calculated), g/cm3 Absorption coefficient, mm–1 F(000) Crystal size, mm range <...>

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