Chandrasekhar Vadapalli, Azhakar Ramachandran, Senapati Tapas, Thilagar Pakkirisamy, Ghosh Surajit, Verma Sandeep, Boomishankar Ramamoorthy, Steiner Alexander, Kögerler Paul
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, UP 208016, India.
Dalton Trans. 2008 Mar 7(9):1150-60. doi: 10.1039/b712876b. Epub 2008 Jan 7.
The reaction of cyclohexylphosphonic acid (C(6)H(11)PO(3)H(2)), anhydrous CuCl(2) and 2,2'-bipyridine (bpy) in the presence of triethylamine followed by a metathesis reaction with KNO(3) afforded Cu(4)(mu-Cl)(2)(mu(3)-C(6)H(11)PO(3))(2)(bpy)(4)(2) (1). In an analogous reaction involving Cu(OAc)(2).H(2)O, the complex Cu(4)(mu-CH(3)COO)(2)(mu(3)-C(6)H(11)PO(3))(2)(2,2'-bpy)(4)(2) (2) has been isolated. The three-component reaction involving Cu(NO(3))(2).3H(2)O, cyclohexylphosphonic acid and 2,2'-bipyridine in the presence of triethylamine afforded the tetranuclear assembly Cu(4)(mu-OH)(mu(3)-C(6)H(11)PO(3))(2)(2,2'-bpy)(4) (H(2)O)(2)(3) (3). Replacing 2,2'-bipyridine with 1,10-phenanthroline (phen) in the above reaction resulted in Cu(4)(mu-OH)(mu(3)-C(6)H(11)PO(3))(2)(phen)(4)(H(2)O)(2)(3) (4). In all the copper(II) phosphonates (1-4) the two phosphonate ions bridge the four copper(II) ions in a capping coordination action. Each phosphonate ion bridges four copper(II) ions in a mu(4), eta(3) coordination mode or 4.211 of the Harris notation. Variable-temperature magnetic studies on reveal that all four complexes exhibit moderately strong intramolecular antiferromagnetic coupling. The DNA cleavage activity of complexes 1-4 is also described. Compounds 1 and 3 were able to completely convert the supercoiled pBR322 DNA form I to nick form II without any co-oxidant. In contrast, 50% conversion occurred with and 40% with 4. In the presence of magnesium monoperoxyphthalate all four compounds achieved rapid conversion of form I to form II.
在三乙胺存在下，环己基膦酸（C(6)H(11)PO(3)H(2)）、无水CuCl(2)与2,2'-联吡啶（bpy）反应，随后与KNO(3)进行复分解反应，得到Cu(4)(μ-Cl)(2)(μ(3)-C(6)H(11)PO(3))(2)(bpy)(4)(2)（1）。在涉及Cu(OAc)(2).H(2)O的类似反应中，分离出了配合物Cu(4)(μ-CH(3)COO)(2)(μ(3)-C(6)H(11)PO(3))(2)(2,2'-bpy)(4)(2)（2）。在三乙胺存在下，Cu(NO(3))(2).3H(2)O、环己基膦酸与2,2'-联吡啶的三组分反应得到四核组装体Cu(4)(μ-OH)(μ(3)-C(6)H(11)PO(3))(2)(2,2'-bpy)(4)(H(2)O)(2)(3)（3）。在上述反应中用1,10-菲咯啉（phen）取代2,2'-联吡啶，得到Cu(4)(μ-OH)(μ(3)-C(6)H(11)PO(3))(2)(phen)(4)(H(2)O)(2)(3)（4）。在所有的铜（II）膦酸盐（1 - 4）中，两个膦酸根离子以封端配位作用桥连四个铜（II）离子。每个膦酸根离子以μ(4)，η(3)配位模式或哈里斯符号的4.211桥连四个铜（II）离子。对其进行变温磁性研究表明，所有四种配合物都表现出中等强度的分子内反铁磁耦合。还描述了配合物1 - 4的DNA切割活性。化合物1和3能够在没有任何共氧化剂的情况下将超螺旋pBR322 DNA形式I完全转化为缺口形式II。相比之下，化合物2实现了50%的转化，化合物4实现了40%的转化。在单过氧邻苯二甲酸镁存在下，所有四种化合物都能快速将形式I转化为形式II。
