摘要
本文合成了五种以氯冉酸二价阴离子为桥联配体的Cu(Ⅱ)单核([CuLCA]·H_2O)和双核([Cu_2L_2CA](ClO_4)_2)配合物:[Ca(phen)CA]·H_2O(1),[Cu_2(phen)_2CA](ClO_4)_2(2),[Cu(NO_2-phen)CA]·H_2O(3),[Cu_2(NO_2-phen)_2CA](ClO_4)_2(4)和[Cu_2(bpy)_2CA](Clo_4)_2(5).经元素分析、红外、固体紫外、顺磁共振、磁化率及变温磁化率的测定对上述各配合物进行了表征.配合物1,3可能是通过水分子中的氢键将两个[CuLCA]单元联接而缔合的假双聚体.配合物2,4,5则由阳[Cu_2L_2CA]^(2+)阳离子和弱配位的ClO_4^-阴离子所组成.双核配合物中Cu(Ⅱ)离子的几何构型可能为畸变的四方锥.所有五种配合物均难溶于水及常见有机溶剂.上述配合物的室温ESR谱呈现△M_s=2的从单重态到三重态的半场跃迁.配合物2,5的变温磁化率(4—300K)已测得,利用Heisenberg模型确定交换参数J值为-29.2和-25.7cm^(-1).表明在此类桥联配合物中,两核间存在着反铁磁性交换耦合作用.
Five new copper(Ⅱ)complexes containing bidentate terminal ligands and dianions of chloranilio acids(CA) have been synthesized, namely [Cu(phen)CA]. H_2O (1; phen=o-phenanthroline), [Cu_2(phen)_2CA](ClO_4)_2(2), [Cu(NO_2-phen)CA]·H_2O(3; NO_2-phen=5-Nitro-o-phenanthroline), [Cu_2 (NO_2-phen)_2CA](ClO_4)_2(4), and [Cu_2(byp)_2CA] (C1O_4)_2(5; bpy=2, 2'-biphridyl). CA acts as bridging ligand in these compounds. All complexes have been characterized by elemental analyses, IR, electronic spectra, ESR, susceptibility and variable-temperature magnetic susceptibility. Complex 1, 3 might be associated in pseudodimeric entities formed by two [CuLCA]·H_2O moieties connected via hydrogen bonding whereas the structures of 2, 4 and 5 are built up by dimeric [Cu_2L_2CA]^(2+) cations and weak coordinated ClO_4^-anions. The copper(Ⅱ) ion coordination geometry ia probably distorted square pyramidal in the binuclear complexes. These complexes are very poorly soluble in water or common organic solvenos. Roomtemperature ESR spectra of all the complexes studied show the △M_S=2 half-field transitions (Singlet-to-triplet). The variable-temperature magnetic susceptibilities of 2 and 5 have been measured (4-300 K). Based on the Heisenbery model, the exchange parameter, J, was found to be-29.2 and-25.7cm^(-1) for 2 and 5, respectively. An antiferromagnetic exchange interaction was suggested between the metal ions in these complexes.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1991年第4期376-381,共6页
Acta Chimica Sinica
基金
南开大学元素有机化学重点实验室基金
