二甲苯基桥连双（1,4,7-三氮杂环壬烷）配体的双核铜（II）配合物

Binuclear copper(II) complexes of xylyl-bridged bis(1,4,7-triazacyclononane) ligands.

作者信息

Fry Fiona H, Spiccia Leone, Jensen Paul, Moubaraki Boujemaa, Murray Keith S, Tiekink Edward R T

机构信息

School of Chemistry, P.O. Box 23, Monash University, Victoria 3800, Australia.

出版信息

Inorg Chem. 2003 Sep 8;42(18):5594-603. doi: 10.1021/ic0342595.

DOI:10.1021/ic0342595

PMID:12950207

Abstract

Copper(II) complexes of three bis(tacn) ligands, [Cu(2)(T(2)-o-X)Cl(4)] (1), Cu(2)(T(2)-m-X)(H(2)O)(4)(4).H(2)O.NaClO(4) (2), and [Cu(2)(T(2)-p-X)Cl(4)] (3), were prepared by reacting a Cu(II) salt and L.6HCl (2:1 ratio) in neutral aqueous solution [T(2)-o-X = 1,2-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene; T(2)-m-X = 1,3-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene; T(2)-p-X = 1,4-bis(1,4,7-triazacyclonon-1-ylmethyl)benzene]. Crystals of Cu(2)(T(2)-m-X)(NPP)(mu-OH).H(2)O (4) formed at pH = 7.4 in a solution containing 2 and disodium 4-nitrophenyl phosphate (Na(2)NPP). The binuclear complexes Cu(2)(T(2)-o-XAc(2))(H(2)O)(2)(2).4H(2)O (5) and Cu(2)(T(2)-m-XAc(2))(H(2)O)(2)(2).4H(2)O (6) were obtained on addition of Cu(ClO(4))(2).6H(2)O to aqueous solutions of the bis(tetradentate) ligands T(2)-o-XAc(2) (1,2-bis((4-(carboxymethyl)-1,4,7-triazacyclonon-1-yl)methyl)benzene and T(2)-m-XAc(2) (1,3-bis((4-(carboxymethyl)-1,4,7-triazacyclonon-1-yl)methyl)benzene), respectively. In the binuclear complex, 3, three N donors from one macrocycle and two chlorides occupy the distorted square pyramidal Cu(II) coordination sphere. The complex features a long Cu...Cu separation (11.81 A) and intermolecular interactions that give rise to weak intermolecular antiferromagnetic coupling between Cu(II) centers. Complex 4 contains binuclear cations with a single hydroxo and p-nitrophenyl phosphate bridging two Cu(II) centers (Cu...Cu = 3.565(2) A). Magnetic susceptibility studies indicated the presence of strong antiferromagnetic interactions between the metal centers (J = -275 cm(-1)). Measurements of the rate of BNPP (bis(p-nitrophenyl) phosphate) hydrolysis by a number of these metal complexes revealed the greatest rate of cleavage for Cu(2)(T(2)-o-X)(OH(2))(4) (k = 5 x 10(-6) s(-1) at pH = 7.4 and T = 50 degrees C). Notably, the mononuclear Cu(Me(3)tacn)(OH(2))(2) complex induces a much faster rate of cleavage (k = 6 x 10(-5) s(-1) under the same conditions).

摘要

通过在中性水溶液中使铜（II）盐与L.6HCl（2:1比例）反应，制备了三种双（tacn）配体的铜（II）配合物，[Cu(2)(T(2)-o-X)Cl(4)]（1）、Cu(2)(T(2)-m-X)(H(2)O)(4)(4).H(2)O.NaClO(4)（2）和[Cu(2)(T(2)-p-X)Cl(4)]（3）[T(2)-o-X = 1,2-双（1,4,7-三氮杂环壬-1-基甲基）苯；T(2)-m-X = 1,3-双（1,4,7-三氮杂环壬-1-基甲基）苯；T(2)-p-X = 1,4-双（1,4,7-三氮杂环壬-1-基甲基）苯]。在含有2和4-硝基苯基磷酸二钠（Na(2)NPP）的溶液中，pH = 7.4时形成了Cu(2)(T(2)-m-X)(NPP)(μ-OH).H(2)O（4）的晶体。通过向双（四齿）配体T(2)-o-XAc(2)（1,2-双（（4-（羧甲基）-1,4,7-三氮杂环壬-1-基）甲基）苯）和T(2)-m-XAc(2)（1,3-双（（4-（羧甲基）-1,4,7-三氮杂环壬-1-基）甲基）苯）的水溶液中加入Cu(ClO(4))(2).6H(2)O，分别得到了双核配合物Cu(2)(T(2)-o-XAc(2))(H(2)O)(2)(2).4H(2)O（5）和Cu(2)(T(2)-m-XAc(2))(H(2)O)(2)(2).4H(2)O（6）。在双核配合物3中，来自一个大环的三个氮供体和两个氯占据了扭曲的四方锥铜（II）配位球。该配合物的特点是铜……铜间距长（11.81 Å）以及分子间相互作用，这导致铜（II）中心之间存在弱的分子间反铁磁耦合。配合物4包含双核阳离子，其中单个羟基和对硝基苯基磷酸桥连两个铜（II）中心（Cu……Cu = 3.565(2) Å）。磁化率研究表明金属中心之间存在强反铁磁相互作用（J = -275 cm(-1)）。对这些金属配合物中一些对双（对硝基苯基）磷酸（BNPP）水解速率的测量表明，Cu(2)(T(2)-o-X)(OH(2))(4)的裂解速率最大（在pH = 7.4和T = 50℃时k = 5×10(-6) s(-1)）。值得注意的是，单核Cu(Me(3)tacn)(OH(2))(2)配合物诱导的裂解速率要快得多（在相同条件下k = 6×10(-5) s(-1)）。