Matsumoto Naohide, Motoda Yuri, Matsuo Toshihiro, Nakashima Toshio, Re Nazzareno, Dahan Francoise, Tuchagues Jean-Pierre
Department of Chemistry, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan, Faculty of Education, Oita University, Dan-noharu 700, Oita 870-1192, Japan, Dipartmento di Chimica, Universita di Perugia, via Elce di Sotto 8, 06100 Perugia, Italy, and Laboratoire de Chimie de Coordination du CNRS, UP 8241, 205 Route de Narbonne, 31077 Toulouse Cedex, France.
Inorg Chem. 1999 Mar 22;38(6):1165-1173. doi: 10.1021/ic981158b.
The monomer <--> oligomer interconversion of the reported metal complexes is generated by proton abstraction/supply as a common external information input. The mononuclear copper(II) complexes 1 and 2 with [CuCl(2)(HL(n)())] chemical formula have been prepared (HL(1) = N-(2-methylimidazol-4-ylmethylidene)-2-aminoethylpyridine; HL(2) = N-(2-phenylimidazol-4-ylmethylidene)-2-aminoethylpyridine). The crystal structures were determined. 1.H(2)O, C(12)H(16)N(4)OCl(2)Cu: a = 13.773(2) Å, b = 8.245(2) Å, c = 13.861(2) Å, beta = 110.10(1) degrees, monoclinic, P2(1)/n, and Z = 4. 2, C(17)H(16)N(4)Cl(2)Cu: a = 7.6659(7) Å, b = 16.287(1) Å, c = 14.103(1) Å, beta = 95.058(7) degrees, monoclinic, P2(1)/c, and Z = 4. Complexes 1.H(2)O and 2 assume a pentacoordinated square pyramidal geometry with a N(3)Cl(2) donor set consisting of the nitrogen atoms of the protonated tridentate ligand and two chloride ions in the solid state, while in aqueous solution the Cu(II) ion is tetracoordinated (N(3)Ow donor set). When 1 and 2 are treated with an equimolar amount of sodium hydroxide or triethylamine, the deprotonation of the imidazole moiety promotes a self-assembly process, arising from coordination of the imidazolate nitrogen atom to a Cu(II) ion of an adjacent unit, to yield compounds 1'.4H(2)O as the perchlorate salt, and 2'a.6H(2)O as the perchlorate salt and( )()2'b as the hexafluorophosphate salt, respectively. 1'.4H(2)O, C(12)H(15)N(4)O(5)ClCu: a = b = 13.966(2) Å, c = 33.689(3) Å, tetragonal, I4(1)/a, and Z = 16. 2'a.6H(2)O, C(51)H(51)N(12)O(15)Cl(3)Cu(3): a = 15.177(3) Å, b = 15.747(3) Å, c = 14.128(3) Å, alpha = 100.06(2) degrees, beta = 110.37(2) degrees, gamma = 63.54(1) degrees, triclinic, P&onemacr;, and Z = 2. 2'b, C(17)H(15)N(9)F(6)PCu: a = b = 29.812(5) Å, c = 11.484(3) Å, trigonal, R&thremacr;, and Z = 18. The nuclearity of the self-assembled molecules and their detailed structure were confirmed to be cyclic imidazolate-bridged tetranuclear for 1'.4H(2)O and hexanuclear for 2'a.6H(2)O and 2'b, respectively, through single-crystal X-ray analyses and FAB-MS spectra. Variable-temperature experimental magnetic susceptibility data were well reproduced by using the Heisenberg model based on a cyclic tetranuclear structure for 1' and a cyclic hexanuclear structure for 2'a and 2'b. The reversible interconversion between the protonated monomeric and deprotonated oligomeric species were confirmed by pH-dependent potentiometric and electronic spectral titrations in aqueous solution, whereas the Pd(II) complex did not show a perfect disassembly process.
所报道的金属配合物的单体<-->低聚物相互转化是通过质子夺取/供应产生的，作为一种常见的外部信息输入。已经制备了化学式为[CuCl(2)(HL(n)())]的单核铜(II)配合物1和2（HL(1)=N-(2-甲基咪唑-4-基亚甲基)-2-氨基乙基吡啶；HL(2)=N-(2-苯基咪唑-4-基亚甲基)-2-氨基乙基吡啶）。测定了晶体结构。1.H(2)O，C(12)H(16)N(4)OCl(2)Cu：a = 13.773(2) Å，b = 8.245(2) Å，c = 13.861(2) Å，β = 110.10(1)°，单斜晶系，P2(1)/n，Z = 4。2，C(17)H(16)N(4)Cl(2)Cu：a = 7.6659(7) Å，b = 16.287(1) Å，c = 14.103(1) Å，β = 95.058(7)°，单斜晶系，P2(1)/c，Z = 4。配合物1.H(2)O和2在固态时呈现五配位的四方锥几何构型，其N(3)Cl(2)供体组由质子化三齿配体的氮原子和两个氯离子组成，而在水溶液中Cu(II)离子是四配位的（N(3)Ow供体组）。当1和2用等摩尔量的氢氧化钠或三乙胺处理时，咪唑部分去质子化促进了自组装过程，这是由于咪唑氮原子与相邻单元的Cu(II)离子配位，分别得到高氯酸盐形式的化合物1'.4H(2)O和高氯酸盐形式的2'a.6H(2)O以及六氟磷酸盐形式的( )()2'b。1'.4H(2)O，C(12)H(15)N(4)O(5)ClCu：a = b = 13.966(2) Å，c = 33.689(3) Å，四方晶系，I4(1)/a，Z = 16。2'a.6H(2)O，C(51)H(51)N(12)O(15)Cl(3)Cu(3)：a = 15.177(3) Å，b = 15.747(3) Å，c = 14.128(3) Å，α = 100.06(2)°，β = 110.37(2)°，γ = 63.54(1)°，三斜晶系，P&onemacr;，Z = 2。2'b，C(17)H(15)N(9)F(6)PCu：a = b = 29.812(5) Å，c = 11.484(3) Å，三方晶系，R&thremacr;，Z = 18。通过单晶X射线分析和FAB-MS光谱证实，自组装分子的核数及其详细结构对于1'.4H(2)O分别为环状咪唑桥连四核，对于2'a.6H(2)O和2'b分别为六核。基于1'的环状四核结构和2'a及2'b的环状六核结构，使用海森堡模型很好地再现了变温实验磁化率数据。通过水溶液中pH依赖的电位滴定和电子光谱滴定证实了质子化单体和去质子化低聚体物种之间的可逆相互转化，而钯(II)配合物没有显示出完美的解离过程。
