Crystal structure of a chloride-bridged copper(II) dimer: piperazine-1,4-dium bis(di-μ-chlorido-bis[(4-carboxypyridine-2-carboxylato-κ²N,O²)chloridocuprate(II)]

Abstract

A new centrosymmetric chloride-bridged CuII dimeric anion, in which one carboxyl group of the pyridine-2,4-di­carb­oxy­lic acid ligand remains protonated, is present in the title structure, together with a diprotonated piperazine as a charge-compensating agent.

Preferential Formation of Side‐Pocket‐Substituted Zinc Phthalocyanines Emitting Beyond 800 nm

“…The bridging chloride atoms have a Li−Cl bond length of 2.231(2) Å, and an Cl−Li−Cl angle of 116.6(11)°. This bond angle is significantly larger than those typically observed for chloride bridged dimers, which commonly fall between 90–100°, [50,51] likely due to the steric hindrance of the Pc‐ligands to which the Li atoms are coordinated. We have found no other examples of a structurally characterized side‐pocket metallated PcM; all other examples of PcMs hosting side‐pocket cations incorporated either protons or, in one case, N‐methylation [26,32,52,53] .…”

Solvent-Mediated Synthesis of M(II)-Coordination Polymer Part 1: Crystal Structure of Poly(1,2-di(4-pyridyl)ethylene-k2N,N')-bis(1,4-benzenediacetato-k4O,O′,O′′,O′′')zinc(II)], C22H18ZnN2O4

“…A number of carboxylate ligands with aromatic backbones are frequently used in the design of metal-organic frameworks with desirable properties. Versatile carboxylate ligands derived from 1,4-benzenedicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, or pyridine-2,4-dicarboxylic acid are commonly used owing to their abundant carboxylate groups possessing high affinity to metal cations [7][8][9]. Other functionalized ligands such as 1,2-bis(4-pyridyl)ethylene, 1,4-benzenediacetic acid, 4,4 -bipyridylethene, or 3-nitro-1,2-benzenedicarboxlic acid have also been extensively used under diverse synthetic conditions to prepare MOFs [10][11][12][13][14][15][16][17], which are used in several applications [18][19][20][21][22].…”