A series of new 3-D boratopolyoxovanadates containing five types of [KxOy]n building units

A series of new 3-D boratopolyoxovanadates {K2V12B18O54(OH)(6)(H2O)[K-8(H2O)(16)]}center dot 3H(2)O (1), {K10V12B18O54(OH)(6)(H2O)}center dot 14H(2)O (2), {V12B18O54(OH)(6)(H2O)[K-6(H2O)12]}center dot 2(H(2)dien)center dot 3H(2)O (3, dien = diethylenetriamine), {V6B20O44(OH)(8)(H2O)[K-8(H2O)(6)]} (4), and {V6B20O44(OH)(8)(H2O)[K(H2O)](2)}center dot 2(H(3)dien)center dot 6H(2)O (5) have been hydrothermally synthesized and structurally characterized. These compounds contain five types of [KxOy](n) building units, namely, a dimeric [K2O16] unit for 5, a 1-D [K3O12](n) chain for 3, a 3-D [K5O10](n) sub-network for 1, a 3-D [K5O12](n) sub-network for 2, and a 3-D [K4O7](n) sub-network for 4. The 3-D frameworks of both 1 and 2 are built up from a different 3-D inorganic [KxOy](n) sub-network and entrapped [V12B18O54(OH)(6)(H2O)](10-)(denoted as [V12B18]) clusters, respectively. 3 contains [V12B18] clusters and 1-D [K3O12](n) chains, which are interconnected to form a 3-D {V12B18O54(OH)(6)(H2O)[K-6(H2O)(12)]}(n) architecture with 1-D tunnels filled with protonated H(2)dien(2+) ions. The 3-D architecture of 4 is constructed by another rare 3-D inorganic [K4O7](n) sub-network and entrapped [V6B20O44(OH)(8)(H2O)] (denoted as V6B20) clusters. Compounds 1, 2 and 4 represent rare examples of extended POVs with the 3-D inorganic [KxOy](n) sub-networks. 5 contains [V6B20] clusters and dimeric [K2O16] units, which are interconnected to give a 3-D {B20V6O44(OH)(8)(H2O)[K(H2O)](2)}(n) architecture with 1-D tunnels filled with protonated H(3)dien(3+) ions. Although a few boratopolyoxovanadates contain the [V6B20] cluster, they display either a discrete [V6B20] cluster or a low-dimensional extended structure. Therefore, both 4 and 5 are rare examples of 3-D boratopolyoxovanadate architectures based on the [V6B20] clusters. The magnetic susceptibilities of both 4 and 5 show the antiferromagnetic interaction between V-IV cations. Their spectroscopic properties were also investigated.