Copper Coordination Polymers with Infinite Chloride Ion Channels and Different Directions of the Jahn‐Teller Distortion, Built from Tris(1,2,4‐triazolyl)borate as a Modified Tris(pyrazolyl)borate Ligand

Abstract

found Cul/CuZ-Cl = 2.572(2)/2.328(2), Cul/CuZ-N = 2.585(5)/2.077(4); 2.000(4)/1.979(5); 2.100(5)/2.734(5); 2.005(4)/1.994(4); 2.024(5)/2.369(5). In the 3-D coordination polymer 8 one of the two different Cu centers is chelated by the three endodentate nitrogen donors, while the other Cu center i s coordinated by three exodentate nitrogen atoms. The coordination sphere is completed in both cases by two hydroxo bridges to symmetry-related C u centers. The metalligand connectivity creates infinite channels with helical walls which contain the solvated chloride anions.The results presented here are part of an investigation of the rational assembly of coordination polymers and polynuclear metal complexes containing modifications of the popular poly@.vrazol-$)borate ligands (I) ['], such as hydrotris-and dihydrobis(l,2,4-triazolyflborate (2. 3)[2-41 or dihydrobis(telrazoly1)borale (4)[ips1. The additional donor atoms in 2-4 extend the molecular coordination "chemistry" of 1 to the dimension of the solid state by thc bridging action of the ligand and/or by the formation of hydrogen bonds with water of crystallization as an important elcment of the crystal architecture. Depending on the metal, the poly(triazoly1)borate ligands 2 and 3 were found to be able to function either as chelate ligands or as bridges between metal center~I~,~I. We demonstrate here that five or even all six nitrogen donor atoms o f the hydrotris-(trialzoly1)borate ligand 2 can cngage in metal coordination to give a polynuclear complex, schcinatically shown in 5, as part of a twoor three-dimensional framework, with additional interesting features. The crystal engineering of materials coinposed of inifinite two-and three-dimensional frameworks is an area of intense researchLh].When the labile homoleptic cobalt chelate complex 6[2a,31 is treated with CuClz in water a ligand exchange takes place to give cobalt-free copper compounds of 2 as products. The exact nature of the product depends on the reaction and work-up conditions as outlined in Scheme 1. A slow reaction at elevated temperature yields light blue needle-shaped crystals (7) with a borate ligand-tocopper-to-chlorine ratio of 1 : 1 : 1 directly from the reaction mixture. In contrast. a fast reaction gives a blue precipitate of yet unknown composition (but diffcrent from 7) which was recrystallized from Compounds 7 and 8 cxist as two-and three-dimcnsional coordination polymers, respectively, with two different copper enters each. according to single-crystal X-ray analyses. In 7 the CuC1N5 polyhedra of both copper ions arc approximately tctragonally elongated octahedra, as expccted due to vibronic Jahn-Teller coupling, and the polyhedra are formed by three endodentate and two exodentate nitrogen atoms from the triazolyl rings and a chlorine atom (Figure 1). Two of the triazolyl rings on each borate ligand bridge CuCl2[6l.

Synthetic Bioinorganic Chemistry: Scorpionates Turn 50

“…The first applications of Ttz RR 0 ligands to bioinorganic chemistry involved the preparation of copper coordination polymers that possess some structural features reminiscent of those of hemocyanin (i.e., binding of copper to three His residues) [94]. A copper(I) complex that incorporates both the parent Ttz ligand (R¼R 0 ¼H) and a water-soluble phosphine, (Ttz)Cu{PPh 2 ( p-C 6 H 4 CO 2 H)}, exhibits moderate superoxide scavenging activity [95].…”

Redetermination of diaquatetrakis(dimethylformamide-κO)magnesium dichloride

“…Hydrogen bonding as a primary interaction in crytal engineering and supramolecular chemistry is of continous interest (Aakeröy et al, 2010). The hydrogen bonding between the aqua ligands and the chloride counter anions is in the typical range (Dorn et al, 2005;Janiak et al, 1996). The cyclic hydrogen bond motif ( Fig.1) which is formed by two aqua ligands of neigboring complexes and two chloride anions features the well known R 2 4 (8) motif (Etter et al, 1990).…”

“…For related structures, see: Lebioda & Lewiń ski (1980); Castro et al (2010). For discussion of hydrogen bonds, see: Etter et al (1990); Janiak et al (1996). Dorn et al (2005); Aakerö y et al (2010).…”

The hydridotris(3-nitro-1,2,4-triazol-1-yl)borate, a new nitro-substituted electron withdrawing polydentate “scorpionate”-type ligand and related copper and silver phosphane complexes

“…Evidence of the distinctive role of the exo-ring-nitrogen atoms, N(4), in tris(1,2,4triazolyl)borate complexes comes from a combined X-ray crystallography and theoretical study by Janiak [72], later confirmed by 15 N-NMR studies [80], showing that the N (4) nitrogen atom in [HB(tz) 3 ]has more charge on it than the N-2 nitrogen. Coordination of the exodentate N(4) favors a 2D or a 3D coordination polymer formation [81,82], nonetheless, it is the N(2) that usually coordinates to the metal presumably due to formation of an ideal chelate ring size of six atoms [66,83] [62,70,84,85]. This nitro-substituted scorpionate ligands could be of interest due to their high coordinative flexibility from endoto exo-polydentate coordination mode (Figure 3b).…”