Copper 1D coordination polymers and dimers: Role of the carboxylate and the ammonium cation, crystal structures and magnetic studies

摘要: Abstract The 1D coordination polymers [Cu2(syn,syn-η1:η1:μ-RCOO)4(anti,anti-η1:η1:μ-RCOO)(Et3NH)]n, R = Me (1) and H (2), the dimer [Cu2(syn,syn-η1:η1:μ-PhCOO)4(anti-η1-PhCOO)2(Et3NH)2] (3) are formed by reaction of copper carboxylates with corresponding carboxylic acid NEt3. Moreover, compound [Cu2(syn,syn-η1:η1:μ-MeCOO)4(anti-η1-MeCOO)2(Et2NH2)2] (4) can be obtained use NHEt2. crystal structures 1·CH3CN 2 comprise linear anionic chains paddle-wheel [Cu2(RCOO)4], bridged together anti,anti-η1:η1:μ acetato or formato ions. negative charges balanced hydrogen-bonded triethylammonium countercations, in 1 acetonitrile molecules hosted voids between chains. In compounds 3 4, two anti-η1-benzoato -acetato anions occupy apical positions dimers Et3NH+ Et2NH2+ cations balancing charges, without formation polymer dimeric units held a network hydrogen bonds diethylammonium cations. order to evaluate effect simultaneous presence syn,syn- ions on Cu–Cu magnetic communication, susceptibility has been measured. Data were fitted model based an alternating chain Heisenberg–Zeeman Hamiltonian (−2J Ŝ1·Ŝ2 convention). results show strong antiferromagnetic coupling within 2J1 = −(310.8 ± 0.1) cm−1 weak 2J2 = −(25 ± 1) cm−1. latter is significant since its introduction fit leads well-behaved error surface ∼35% decrease sum squared residuals. electron paramagnetic resonance (EPR) spectra powder sample have recorded 5 295 K, they typical triplet state (zero field splitting |D| = 0.34 cm−1).