Cation-Dependent Nuclearity of the Copper−Azido Moiety:  Synthesis, Structure, and Magnetic Study

Abstract

Mono-, di-, and trinuclear copper-azido moieties have been synthesized by varying the size of the countercations. [Bu4N]+ yielded a [Cu2(N3)6]2- copper-azido moiety in [Bu4N]2[Cu2(mu(1,1)-N3)2(N3)4], 1, and [Pr4N]+ yielded a [Cu3(N3)8]2- moiety in {[Pr4N]2[Cu3(mu(1,1)-N3)4(N3)4]}n, 2, in which symmetry-related [Cu3(N3)8]2- moieties are doubly mu(1,1)-azido bridged to form unprecedented infinite zigzag chains parallel to the crystallographic a-axis. In the case of [Et4N]+, the mononuclear species [Et4N]2[Cu(N3)4], 3, has been formed. All complexes have been characterized structurally by single-crystal X-ray analysis: 1, C32H72N20Cu2, triclinic, space group P, a = 10.671(9) A, b = 12.239(9) A, c = 10.591(5) A, alpha = 110.01(4) degrees , beta = 93.91(5) degrees , gamma = 113.28(5) degrees , V = 1160.0(1) A3; 2, C24H56N26Cu3, monoclinic, space group P2(1)/n, a = 8.811(2) A, b = 37.266(3) A, c = 13.796(1) A, beta = 107.05(1) degrees , V = 4330.8(10) A(3); 3, C16H40N14Cu, tetragonal, space group I4/m, a = b = 10.487(1) A, c = 12.084(2) A, V = 1328.9(3) A3. The variable-temperature magnetic susceptibility measurements showed that although the magnetic interaction in [Bu4N]2[Cu2(mu(1,1)-N3)2(N3)4], 1, is antiferromagnetic (J = -36 cm(-1)), it is ferromagnetic in {[Pr4N]2[Cu3(mu(1,1)-N3)4(N3)4]}n, 2 (J = 7 cm(-1)). As expected, the [Et4N]2[Cu(N3)4] complex, 3, is paramagnetic.

Thiocyanato-copper(II) complexes derived from a tridentate amine ligand and from alanine

“…In general, five-coordinate Cu(II) species with an intermediate stereochemical environment ranging between trigonal bipyramidal (TBP) and square pyramidal (SP) were found to be the major species that are formed in solid and in solution states [3,4,[18][19][20][21][22][23][24][25]. The nature of the coligand around the central Cu 2? ion plays a crucial role in adopting one of the two geometries.…”

Homoleptic manganese(II)–azide layer: Synthesis, structural characterization and magnetic properties

“…Particular interest has been focused on the azido ligand for its diversity in coordination modes and efficiency in magnetic coupling, and a large number of azido-bridged complexes with different dimensionalities and various topologies have been reported in the literature [4][5][6]. These complexes can be divided into two classes besides the neutral binary metal azides [7,8]: (i) heteroleptic complexes with coligands [9][10][11][12][13][14][15][16] and (ii) homoleptic anionic ones with charge-balancing cations that may act as templates for the anionic metal-azide substructures [17][18][19][20][21][22]. Considerable progress has been made in the synthesis and characterization of the former class, but the latter class has been relatively rarely explored.…”

“…Several systems with the alkali-metal Cs + or alkyl ammoniums such as R 4 N + (R = Me, Et, n-Pr) and dmenH 2 2+ (N,N 0 -dimethylethylenediammonium) have been reported. Most of them are Cu(II) compounds with discrete (0D) or extended (1D) Cu x (N 3 ) y substructures [17][18][19]. Two Mn(II) compounds in which the cations (Cs + or Me 4 N + ) are embedded in the three-dimensional anionic host frameworks of [Mn(N 3 ) 3 ] n have also been reported [20][21][22].…”

An Imidazolate‐ and Azide‐Bridged Copper(II) Coordination Polymer Consisting of Alternating Di‐ and Mononuclear Units

“…To date, the double EO-azide-bridged dinuclear core [Cu(μ 1,1 -N 3 ) 2 Cu] 2+ has been studied from the magnetostructural correlation perspective. [29][30][31][32][33][34][35][36][37][38][39] The dinuclear core of the D unit is centrosymmetric (Figure 2, a). Each Cu ion in the D unit adopts a square pyramidal geometry with the basal plane formed by four nitrogen atoms from two EOazides, one Him and one im, and with the apical site occupied by a nitrogen atom from an EE-azide.…”