Molecular-Programmed Self-Assembly of Homo- and Heterometallic Penta- and Hexanuclear Coordination Compounds: Synthesis, Crystal Structures, and Magnetic Properties of Ladder-Type CuII

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• 作者：Emilio Pardo ; Rafael Ruiz-Garcí ; a ; Francesc Lloret ; Miguel Julve ; Joan Cano ; Jorge Pas&aacute ; n ; Catalina Ruiz-Pé ; rez ; Yasmine Filali ; Lise-Marie Chamoreau ; Yves Journaux
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：May 28, 2007
• 年：2007
• 卷：46
• 期：11
• 页码：4504 - 4514
• 全文大小：335K
• 年卷期：v.46,no.11(May 28, 2007)
• ISSN：1520-510X

文摘

New homo- and heterometallic, hexa- and pentanuclear complexes of formula {[Cu₂(mpba)₂(H₂O)F][Cu(Me₅dien)]₄}(PF₆)₃·5H₂O (1), {[Cu₂(Me₃mpba)₂(H₂O)₂][Cu(Me₅dien)]₄}(ClO₄)₄·12H₂O (2), {[Cu₂(ppba)₂][Cu(Me₅dien)]₄}(ClO₄)₄ (3),and [Ni(cyclam)]{[Cu₂(mpba)₂][Ni(cyclam)]₃}(ClO₄)₄·6H₂O (4) [mpba = 1,3-phenylenebis(oxamate), Me₃mpba =2,4,6-trimethyl-1,3-phenylenebis(oxamate), ppba = 1,4-phenylenebis(oxamate), Me₅dien = N,N,N'N' ',N' '-pentamethyldiethylenetriamine, and cyclam = 1,4,8,11-tetraazacyclotetradecane] have been synthesized through the useof the "complex-as-ligand/complex-as-metal" strategy. The structures of 1-3 consist of cationic Cu^II₆ entities withan overall [2 × 2] ladder-type architecture which is made up of two oxamato-bridged Cu^II₃ linear units connectedthrough two m- or p-phenylenediamidate bridges between the two central copper atoms to give a binuclearmetallacyclic core of the cyclophane-type. Complex 4 consists of cationic Cu^II₂Ni^II₃ entities with an incomplete [2 ×2] ladder-type architecture which is made up of oxamato-bridged Cu^IINi^II and Cu^IINi^II₂ linear units connected throughtwo m-phenylenediamidate bridges between the two copper atoms to give a binuclear metallacyclophane core. Themagnetic properties of 1-3 and 4 have been interpreted according to their distinct "dimer-of-trimers" and "dimer-plus-trimer" structures, respectively, (H = -J(S_1A·S_3A + S_1A·S_4A + S_2B·S_5B + S_2B·S_6B) - J'S_1A·S_2B). Complexes 1-4exhibit moderate to strong antiferromagnetic coupling through the oxamate bridges (-J_Cu-Cu = 81.3-105.9 cm^-1;-J_Cu-Ni = 111.6 cm^-1) in the trinuclear and/or binuclear units. Within the binuclear metallacyclophane core, aweak to moderate ferromagnetic coupling (J'_Cu-Cu = 1.7-9.0 cm^-1) operates through the double m-phenylenediamidate bridge, while a strong antiferromagnetic coupling (J'_Cu-Cu = -120.6 cm^-1) is mediated by thedouble p-phenylenediamidate bridge.