Hydrothermal syntheses, crystal structures and characterization of new vanadoborates: The novel decorated cage cluster [V6B22O44(OH)10]

Three new vanadoborates [H3teta]3[V12B18O54(OH)6(H2O)]·(H3O)·5H2O (1, teta=triethylenetetramine), [H4teta]2[V6B22O44(OH)10] ·4.5H2O (2) and [H4tepa]2[V6B22O44(OH)10] ·4H2O (3, tepa=tetraethylenepentamine) have been hydrothermally synthesized and structurally characterized. 1 contains cage cluster [V12B18O54(OH)6(H2O)]10− based on one puckered B18O36(OH)6 ring sandwiched between two V6O15 clusters. Both 2 and 3 contain new decorated cage cluster [V6B22O44(OH)10]8− built up from a central band of [V6O18] capped top and bottom by two raft-like polyborate [B11O20(OH)4] units. The magnetic susceptibility of 3 demonstrates the presence of antiferromagnetic interaction between VIV cations. The theoretical band structure and spectroscopic properties have been also studied. - Graphical abstract: The circular [V6O18] fragment sandwiched by the two raft-like polyborate [B11O20(OH)4] units via sharing O atoms form a new cage cluster [V6B22O44(OH)10]8−, which represents a new type. Highlights: ► Novel decorated cage cluster [V6B22O44(OH)10] is observed. ► The mixed valence vanadoborate cluster is found. ► The theoretical band structure and spectroscopic properties have been also studied