【摘要】 本文报导了的晶体结构。晶体属三斜晶系,空间群P₁,晶胞参数:a=10.761（2）,b=13.930（4）,c=15.117（4）;a=114.74（2）°,β=101.82（2）°,γ=95.85（2）°;Z=1。标题化合物为四羧基桥的双核铜（Ⅱ）簇合物,DMF占据端基位置。Cu-Cu距离2.635（2）,有微弱成键作用。SCC-EHMO计算表明前线轨道38A_g,37B_u,21A_u和20B_g能级相当接近,化合物为顺磁性,μ（eff）=1.82B.M.,根据顺磁谱出现的由三组峰组成的一套谱,其中在低场的一组峰分裂7条超精细结构峰,判断化合物顺磁性应是占据38A_g,和37B_u分子轨道上未配对电子的贡献。Cu-Cu的成键和反键的σ,π和δ型轨道都填满电子,因此对成键不起作用。Cu-Cu之间的微弱成键作用,主要是通过铜与羧基桥原子形成的非定域键的34B_u和18A_u分子轨道的贡献。更多还原

【Abstract】 The title compound is synthesized and crystallized in the monoclinic system; space group P1, a=10.761(2), b=13.930(4), c=15.117(2); a=114.74(2)°, β=101.82(2)°, γ=95.85(2)°; Z=1. The final R factor is 0.076 based on 2083 reflections with I≥3σ(I). In the title compound, coppcr(Ⅱ) ions are bridged in pairs by four acetate groups with two DMF molecules occupying the terminal positions. The copper(Ⅱ) ions are 0.20 out of the plane of the four oxygen atoms. The distance between the two copper(Ⅱ) ions is 2.635 which is only slightly greater than 2.55, the interatomic distance in metal copper. A weak bonding existed between the two atoms.SCC-EHMO calculation indicated that the frontier orbitals 38Ag, 37Bu, 21A_u and 20B_g are very close in energy. The remaining two electrons must be placed respectively in the two frontier orbitals 38A_g and 37B_u, resulting in paramagnetism. This can be illustrated by the ESR spectrum. The bonding and antibonding molecular orbitals of Cu-Cu σ,Ⅱ and δ are completely filled. There is no net bonding from those filled electrons. The weak bonding between the two copper(Ⅱ) ions is contributed by the 34B_u and 18A_u molecular orbitals that the electrons delocalized over copper and carboxyl atoms.更多还原