Two Vanadogermanates from 1-Dimensional Chain to 2-Dimensional Network Built from Di-Cd-Substituted Ge–V–O Clusters and Transition Metal Complex Bridges

Two novel vanadogermanates [Cd(en)(H 2 O) 2 ][Cd(en) 2 ][Cd(en)]{[Cd(en)] 2 [Ge 8 V 12 O 42.5 (OH) 5 ]}·2H 2 O ( 1 ) and [Cd(en) 3 ][Cd(en)] 2 {[Cd(en)] 2 [Ge 8 V 12 O 42 (OH) 6 ]}·10H 2 O ( 2, en = ethylenediamine) have been hydrothermally synthesized and structurally characterized by elemental analysis, infrared spectroscopy, powder X-ray diffractions, thermogravimetric analysis, UV–vis spectroscopy, and single-crystal X-ray diffractions. Structural analysis reveals that the Ge–V–O cluster anions in the two compounds are derived from the classical saturated {V 18 O 42 } cluster by replacing four VO 5 square pyramids with four Ge 2 O 7 groups. Especially, the Ge–V–O cluster anion in 2 is a new configuration of Ge–V–O clusters with four Ge 2 O 7 groups and first reported in this work. 1 is the first 1-dimensional (1-D) chain based on the linkage of centrosymmetric dimeric clusters {[Cd(en)] 2 [Ge 8 V 12 O 42.5 (OH) 5 ]} 2 12– and trinuclearity [Cd 3 O 4 (en) 4 (H 2 O) 2 ] 2– complexes. 2 is an unprecedented 2-D network built from unique {[Cd(en)] 2 [Ge 8 V 12 O 42 (OH) 6 ]} 8– clusters and 1-D coordination chains {Cd 3 O 2 (en) 5 } 2+ . Magnetic measurements illustrate that these compounds have overall antiferromagnetic exchange interactions between metal ions.