详细信息	查看全文 | 推荐本文 |

• 作者：Marina V. Kirillova ; Alex ; er M. Kirillov ; M. Fá ; tima C. Guedes da Silva ; Maximilian N. Kopylovich ; Joã ; o J.R. Fra&#xfa ; sto da Silva ; Arm ; o J.L. Pombeiro
• 关键词：Crystal engineering ; Dipicolinic acid ; Heterometallic complexes ; Hydrogen bonds ; Metal-organic frameworks ; Water clusters
• 刊名：Inorganica Chimica Acta
• 出版年：2008
• 期刊代码：40_00201693
• 类别：ch
• 出版时间：5 May 2008
• 卷：361
• 期：6
• 页码：1728-1737
• 文件大小：1887 K

摘要

New heterodinuclear Zn^II/Ni^II (ong>1ong>) and homodinuclear Ni^II/Ni^II (ong>2ong>) water-soluble and air stable compounds of general formula [M(H₂O)₆][M′(dipic)₂] · mH₂O have been easily prepared by self-assembly of the corresponding metal(II) nitrates with dipicolinic acid (H₂dipic) in water solution at room temperature. The compounds have been characterized by IR, UV/Vis and atomic absorption spectroscopies, elemental and X-ray single crystal diffraction (for ong>1ong> · 4H₂O and ong>2ong> · 5H₂O) analyses. 3D infinite polymeric networks are formed via extensive hydrogen bonding interactions involving all coordinated and crystallization water molecules, and all dipicolinate oxygens, thus contributing to additional stabilization of dimeric units, metal-organic chains and 2D layers. In ong>1ong> · 4H₂O, the latter represent a rectangular-grid 2D framework with multiple channels if viewed along the c crystallographic axis, while in ong>2ong> · 5H₂O intercalated crystallization water molecules are associated to form acyclic nonplanar hexameric water clusters and water dimers which occupy voids in the host metal-organic matrix, with a structure stabilizing effect via host–guest interactions. The hexameric cluster extends to the larger (H₂O)₁₀ one with an unusual geometry (acyclic helical octamer with two pendent water molecules) by taking into account the hydrogen bonds to water ligands in [Ni(H₂O)₆]²⁺. The obtained Zn/Ni compound ong>1ong> relates to the recently reported family of heterodimetallic complexes [M(H₂O)₅M′(dipic)₂] · mH₂O (M/M′ = Cu/Co, Cu/Ni, Cu/Zn, Zn/Co, Ni/Co, m = 2, 3), what now allows to establish the orders of the metal affinity towards the formation of chelates with dipicolinic acid (Co^II > Ni^II > Zn^II > Cu^II) or aqua species (Co^II c; Ni^II c; Zn^II c; Cu^II).