Keggin POMs Modified by Bonding to Multitrack Cu(bipy) Chains through Linearly Arrayed Terminal and Bridging Oxygen Atoms of the M 3 O 13 Triad

Two novel complexes based on the Keggin POMs modified by the Cu(4,4′‐bipy) moiety, {[Cu(4,4′‐bipy)] 3 [HSiMo 12 O 40 ]} · 1.5H 2 O ( 1 ) and {[Cu(4,4′‐bipy)] 4 [SiW 12 O 40 ]} · 3H 2 O ( 2 ) (bipy = bipyridine), have been hydrothermally synthesized and characterized by routine physical methods and single‐crystal X‐ray diffraction. Complexes 1 and 2 represent the first examples of fully oxidized Keggin POM anions as pendant polydentate ligands covalently bonded to a multitrack Cu(bipy) polymer chain(s) through linearly arrayed O d ··· O c ··· O d (O d , terminal oxygen; O c , bridging oxygen) atoms of single M 3 O 13 triad(s). In the crystalline lattice of 1 , the 1D chain is constructed from a α‐[SiMo 12 O 40 ] 4– (SiMo 12 ) cluster as a pendant tridentate ligand covalently bonded to three Cu I (4,4′‐bipy) subunits, and the neighbouring polymer strands interconnect with the Keggin fragments geared like the teeth of a zipper. In compound 2 , the 2D extended layer structure is composed of a α‐[SiW 12 O 40 ] 4– (SiW 12 ) cluster as a pendant hexadentate ligand covalently bonded to four Cu I (4,4′‐bipy) subunits and forms a 2D net‐texture structure with a large vacancy (30.9 × 10.6 Å), and the 2D layers are arranged in a parallel staggering fashion to form a 3D framework.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)