Synthesis, characterization and magnetic properties of .mu.-oxalato- and .mu.-oxamido-bridged copper(II) dimers. Crystal and molecular structures of [Cu2(mepirizole)2(C2O4)(H2O)2](PF6)2.cntdot.mepirizole.cntdot.3H2O and [Cu2(mepirizole)2(C2O4)(NO3)2(H2O)]2[Cu2(mepirizole)2(C2O4)(NO3)2]

Syntheses, structures, and spectroscopic properties of binuclear copper(II) complexes containing N,N-bis(2-pyridylmethyl)amine ligands

“…The bite angle formed by Cu and the two oxygens of oxalate (O1-Cu1-O2A) is 77.75 , close to those reported for oxalate-bridged copper(II) [31][32][33]. The Cu(1) Á Á Á Cu(1A) distance is 5.552 Å , close to 5.597 Å [29] and 5.528 Å ; 5.469 Å [31], slightly shorter than 5.608 [30] to 5.631 Å [33], and longer than 5.1-5.4 Å found in dimeric Cu(II) complexes [34][35][36][37][38].…”

Syntheses, Structures and Magnetic Properties of Novel Oxamido‐Bridged Tetranuclear Complexes [Cu3M] (M = Cu, Mn)

“…[12Ϫ14] At the same time, it was also discovered that the oxamido group is an efficient bridging mediator of magnetic exchange between neighbouring metal ions [15] because (i) the lower electronegativity of nitrogen with respect to oxygen leads to the gap between the oxamide-bridge molecular orbitals and the d metal orbitals being smaller; (ii) the metal-nitrogen and metal-oxygen distances are very close and contribute to maintaining a good overlap between the bridge and the d-metal orbitals. [16] Many complexes including this bridge have been synthesised and their magnetic properties characterised.…”

Oxalato‐Bridged Dinuclear Copper(II) Complexes of N‐Alkylated Derivatives of 1,4,7‐Triazacyclononane: Synthesis, X‐ray Crystal Structures and Magnetic Properties

“…A compilation of structural and magnetic properties of related oxalato-bridged copper(II) complexes can be found in Table 5. Curiously, [Cu 2 (tacn) 2 (µ-ox)](ClO 4 ) 2 , which has [12] dpa NO 3 7.2 0.08 5.22 -305 [24] tmen ClO 4 8.4 0.18 5.147/5.167 -385.4 [1] deen ClO 4 3.9 n/r n/r -300 [29] mpz PF 6 13.9 0.24 n/r -402 [30] mpz NO 3 2.1 0.06 n/r -312 [30] mpz NO 3 n/r 0.12 5.217 -284 [31] dpp NO 3 7.3 0.16 5.171(1) -312 [9] bpz Cl 4.9 0.10/0.09 5.134(2) -345 [9] Pz [14] [a] Abbreviations: Me 3 tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane; BzMe 2 tacn = 1-benzyl-4,7-dimethyl-1,4,7-triazacyclononae, tacn = 1,4,7-triazacyclononane; phen = 1,10-phenanthroline; bdpm = bis(3,5-dimethylpyrazol-1-yl)methane; bipy = 2,2Ј-bipyridine; dpa = 2,2Ј-dipyridylamine; tmen = N,N,NЈ,NЈ-tetramethylethylenediamine; deen = N,N-diethylethane-1,2-diamine; mpz = 4-methoxy-2-(5-methoxy-3-methylpyrazol-1-yl)-6-methylpyrimidine; dpp = 2,3-bis(2-pyridyl)pyrazine; bpz = 2,2Ј-bipyrazine; Pz 2 CPh 2 = diphenyldipyrazolylmethane; Pz a very similar bridging motif to both C2 and C3, exhibits relatively weak antiferromagnetic coupling. [19] Both C2 and C3, which have similar J values, have larger φ and h Cu values than the parent tacn complex but this difference does not account for the large difference in the J value.…”