Investigation of Structural Transformation of a Chain-like Silver(I) Pyrazolate into a Triangular Isomer

Abstract

Four silver(I) pyrazolato complexes, namely, [Ag(mdnpz)] n , [(Ag(mdnpz)(NCCH 3 )] n , [Ag(mdnpz)] 3 •2.5H 2 O, and [Ag(mdnpz)] 3 •C 7 H 8 , were synthesized and structurally characterized by single-crystal X-ray diffraction, where mdnpz − denotes 4methyl-3,5-dinitro-pyrazolate and C 7 H 8 stands for toluene. The chain-like [Ag(mdnpz)] n can be prepared by mixing 4-methyl-3,5dinitro-pyrazole and AgNO 3 in methanol. [(Ag(mdnpz)(NCCH 3 )] n , adopting a helical chain structure, was isolated from an acetonitrile solution of [Ag(mdnpz)] n , which may be a key intermediate in the structural transformation.The triangular species can be obtained as adducts with water or toluene from the aforementioned CH 3 CN solution. On the basis of the experimental observations, crystal structures, mass spectrum, and theoretical investigation, the isomeric transformation can be described as a solvent-assisted, acid−base interaction promoted, thermodynamically favored process.

Tetranuclear Copper(I) and Silver(I) Pyrazolate Adducts with 1,1′-Dimethyl-2,2’-bibenzimidazole: Influence of Structure on Photophysics

“…Copper(I) and silver(I) pyrazolate adducts, which often possess isostructural complexes, have a special place in coordination chemistry. Depending on the reaction conditions and substituents in the initial pyrazole, poly- [ 18 ], di- [ 19 , 20 ], tri- [ 21 , 22 ], and tetranuclear [ 23 , 24 ] complexes can be obtained. Cyclic trinuclear complexes ( Scheme 1 , [MPz] 3 ) are more popular because of their planar structures, allowing the formation of supramolecular aggregates via M-M or M…π interactions [ 15 , 22 , 25 ].…”

Structural transformation of copper coordination complexes accompanied with chiral transformation

“…The structural transformation from metastable structures to the most thermodynamically stable compound is universally observed and has attracted widespread attention. [32][33][34] Detailed changes in the crystal structure are exhibited during the transformation and offer the opportunity to explore the reaction mechanism at the atomic level, such as the addition and removal of solvent or guest molecules. 28,[35][36][37][38][39][40][41] Chirality is also a universal feature in nature and living organisms, and chiral complexes show unique properties including circular dichroism (CD), circularly polarized luminescence (CPL), optical rotation, chiroptical switching processes, and nonlinear optical (NLO) activity.…”