A Variety of 1D to 3D Metal−Organic Coordination Architectures Assembled with 1,1′-(2,2′-Oxybis(ethane-2,1-diyl))bis(1<i>H</i>-imidazole)
2008-05-07T00:00:00Z (GMT) by
A new long flexible ligand, L = 1,1′-(2,2′-oxybis(ethane-2,1-diyl))bis(1<i>H</i>-imidazole), has been prepared. The hydrothermal reactions of L with various metal ions (M(II) = Co, Zn, and Cd) as well as a series of aromatic polycarboxylate co-ligands yielded seven new metal−organic frameworks consisting of 1D, 2D, and 3D structures. Complexes <b>1</b>–<b>5</b> are constructed by SBU I (a M<sub>2</sub>L<sub>2</sub> metallocycle), while complexes <b>6</b> and <b>7</b> are assembled by SBU II (left- and right-handed helical [M(L)]<i><sub>n</sub></i> chains). In <b>1</b>and <b>2</b>, the SBUs I are bridged by 1,2-BDC (1,2-benzenedicarboxylate) and 3,5-DNP (3,5-dinitrophthalate) anions with the same coordination modes to generate 1D chains with repeated rings. <b>3</b> exhibits a typically 3-fold interpenetrated 3-connected (10,3)-b net. In <b>4</b>, the Co centers are connected by μ<i><sub>3</sub></i>-OH and carboxylic O atoms to form a cobalt−oxygen tetranuclear cluster. <b>5</b> represents an uncommon example of a 3,4-connected net with (8<sup>3</sup>)<sub>2</sub>(8<sup>5</sup> × 10) topology. In <b>6</b>, the SBUs II are extended by 1,4-BDC (1,4-benzenedicarboxylate) anions to afford highly undulated 2D (4, 4) layers. In <b>7</b>, the [Cd<sub>3</sub>(1,3-BDC)<sub>3</sub>] ladders connect to SBUs II to form a corrugated 2D network. A comparison of all complexes demonstrates that the structural characteristics of L ligand and organic counteranions simultaneously play an important role in the construction of the complexes. In addition, complexes <b>3</b> and <b>7</b> exhibit strong blue photoluminescence, and compound <b>4</b> is an antiferromagnet.