Yasodha Vaduganathan, Govindarajan Subbaiah, Low John N, Glidewell Christopher
Department of Chemistry, Bharathiar University, Coimbatore 641 046, Tamil Nadu, India.
Acta Crystallogr C. 2007 May;63(Pt 5):m207-15. doi: 10.1107/S010827010701459X. Epub 2007 Apr 21.
The structures of five metal complexes containing the 4-oxo-4H-pyran-2,6-dicarboxylate dianion illustrate the remarkable coordinating versatility of this ligand and the great structural diversity of its complexes. In tetraaquaberyllium 4-oxo-4H-pyran-2,6-dicarboxylate, Be(H(2)O)(4), (I), the ions are linked by eight independent O-H...O hydrogen bonds to form a three-dimensional hydrogen-bonded framework structure. Each of the ions in hydrazinium(2+) diaqua(4-oxo-4H-pyran-2,6-dicarboxylato)calcate, (N(2)H(6))[Ca(C(7)H(2)O(6))2(H2O)2], (II), lies on a twofold rotation axis in the space group P2/c; the anions form hydrogen-bonded sheets which are linked into a three-dimensional framework by the cations. In bis(mu-4-oxo-4H-pyran-2,6-dicarboxylato)bis[tetraaquamanganese(II)] tetrahydrate, [Mn2(C(7)H(2)O(6))2(H2O)(8)].4H2O, (III), the metal ions and the organic ligands form a cyclic centrosymmetric Mn2(C(7)H(2)O(6))2 unit, and these units are linked into a complex three-dimensional framework structure containing 12 independent O-H...O hydrogen bonds. There are two independent Cu(II) ions in tetraaqua(4-oxo-4H-pyran-2,6-dicarboxylato)copper(II), [Cu(C(7)H(2)O(6))(H2O)4], (IV), and both lie on centres of inversion in the space group P1; the metal ions and the organic ligands form a one-dimensional coordination polymer, and the polymer chains are linked into a three-dimensional framework containing eight independent O-H...O hydrogen bonds. Diaqua(4-oxo-4H-pyran-2,6-dicarboxylato)cadmium monohydrate, [Cd(C(7)H(2)O(6))(H2O)2].H2O, (V), forms a three-dimensional coordination polymer in which the organic ligand is coordinated to four different Cd sites, and this polymer is interwoven with a complex three-dimensional framework built from O-H...O hydrogen bonds.
五种含有4-氧代-4H-吡喃-2,6-二羧酸盐二价阴离子的金属配合物的结构，展示了该配体卓越的配位多样性及其配合物巨大的结构多样性。在四水合铍4-氧代-4H-吡喃-2,6-二羧酸盐Be(H₂O)₄，(I)中，离子通过八个独立的O-H...O氢键相连，形成三维氢键框架结构。在肼鎓(2+)二水(4-氧代-4H-吡喃-2,6-二羧基)钙酸盐(N₂H₆)[Ca(C₇H₂O₆)₂(H₂O)₂]，(II)中，每个离子位于空间群P2/c的二重旋转轴上；阴离子形成氢键片层，阳离子将其连接成三维框架。在双(μ-4-氧代-4H-吡喃-2,6-二羧基)双[四水合锰(II)]四水合物[Mn₂(C₇H₂O₆)₂(H₂O)₈]·4H₂O，(III)中，金属离子和有机配体形成一个环状中心对称的Mn₂(C₇H₂O₆)₂单元，这些单元连接成一个复杂的三维框架结构，包含12个独立的O-H...O氢键。在四水(氧代-4H-吡喃-2,6-二羧基)铜(II)[Cu(C₇H₂O₆)(H₂O)₄]，(IV)中有两个独立的Cu(II)离子，且都位于空间群P1的反演中心上；金属离子和有机配体形成一维配位聚合物，聚合物链连接成一个包含八个独立O-H...O氢键的三维框架。二水(4-氧代-4H-吡喃-2,6-二羧基)镉一水合物[Cd(C₇H₂O₆)(H₂O)₂]·H₂O，(V)形成三维配位聚合物，其中有机配体与四个不同的Cd位点配位，该聚合物与由O-H...O氢键构建的复杂三维框架相互交织。
