Novel Diazamesocyclic Ligands Functionalized with Pyridyl Donor Group(s) − Synthesis, Crystal Structures, and Properties of Their Copper(II) Complexes

Abstract

Two novel diazamesocyclic ligands based on l,5-diazacyclooctane (DACO) and functionalized with additional pyridyl donor groups, namely 1,5-bis(2-pyridylmethyl)-1,5-diazacyclooctane (L 1 ) and 1-(2-pyridylmethyl)-1,5-diazacyclooctane (L 2 ), have been synthesized and characterized, as have their Cu II complexes. Crystal structure analyses revealed that with Cu(ClO 4 ) 2 L 1 forms a five-coordinate mononuclear complex [Cu II L 1 Cl]ClO 4 (1), whereas L 2 forms a µ-Cl − -bridged dinuclear complex [Cu II (L 2 )Cl] 2 (ClO 4 ) 2 (2). Furthermore, it has been found that the apical chloride anion of 1 may be easily exchanged by azide anion, forming the mononuclear complex [Cu II L 1 (N 3 )]ClO 4 (3). There is a notable difference between 3 and 1 in that 3 forms a quasi-two-dimensional network through intermolecular C−H···O hydrogen bonds and π−π stacking interactions. Each Cu II center in the three com-

A Novel Bis Tridentate Bipyridine Carboxamide Ligand and Its Complexation to Copper(II): Synthesis, Structure, and Magnetism

“…SP I compounds can show both ferromagnetic or antiferromagnetic coupling constants, depending on the nature of the terminal ligands. There are seven SP I compounds with ferromagnetic coupling reported to date in the chemical literature . The J 2 value obtained for the [Cu 2 (L 1 )Cl 2 ] 2 dimer 2 is consistent with the 90° angle rule that the coupling is ferromagnetic for the φ value near to 90°.…”

Electrical Conductivity and Luminescence in Coordination Polymers Based on Copper(I)-Halides and Sulfur-Pyrimidine Ligands

“…The geometry of the CuBr 3 N 2 chromophore can be quantitatively characterized using the parameter τ, as defined by Addison et al The calculated value of τ = 0.42 (relative to one for a regular trigonal bipyramid and zero for a square pyramid) indicates that the coordination geometry around the metal center, although intermediate between the two ideal polyhedrons, is closer to an elongated tetragonal pyramid with the bromide anions placed alternatively on equatorial and apical positions. As a result, the geometry of the complex consists of two square pyramids sharing one base-to-apex edge, with parallel basal planes. − The copper atom is displaced from the mean equatorial plane toward the corresponding axial bromido bridging atoms by 0.311 Å.…”

Ferromagnetic coupling in a unique Cu(II) metallacyclophane with functionalized diazamesocyclic ligands formed by Cu(II)-directed self-assembly: magneto-structural correlations for dichloro-bridged Cu(II) dinuclear complexes

“…A number of investigations have been carried out concerning the magneto-structural correlation and different magnetic behaviors have been found in chloro-bridged Cu II dimers. [5][6][7][8][9]13,14,[23][24][25][26][27][28] To date, three types 5 of pyramidal arrangements in [Cu(m-Cl) 2 Cu] units are found in the literature. The two complexes studied in this paper belong to the same type (I): square pyramids sharing one base-to-apex edge but with parallel basal planes [Scheme 1(a)].…”

“…In our efforts to systematically investigate the control of the structures and magnetic properties as well as the coordination chemistry of diazamesocyclic ligands by modifying their backbone, we have reported a variety of Cu II complexes with different coordination modes and magnetic properties by altering the donor pendants. [12][13][14] In this contribution, we report the syntheses and crystal structures of two chloro-bridged Cu II dimers [Cu(HL 1 )Cl 2 ] 2 (ClO 4 ) 2 (1) and [Cu 2 (L 2 ) 2 Cl 2 ](ClO 4 ) 2 ( 2) with new pyridyl-functionalized diazamesocyclic ligands, 1,5-bis-(pyridin-4-ylmethyl)-1,5-diazacyclooctane (L 1 ) and 1-(pyridin-2-ylmethyl)-1,4-diazacycloheptane (L 2 ). To our knowledge, 1 is the first structurally characterized water-soluble Cu II macrometallacycle assembled in strong acidity conditions.…”