Encapsulation of a 'naked' Br- anion in a polyoxotitanate host

Solvothermal reaction of Ti(OiPr)(4) with CoBr2 in (PrOH)-Pr-i at 150 degrees C gives the ion-separated compound [Ti12O15((OPr)-Pr-i)(17)](+)[(BrCo)(6)Ti15O24((OPr)-Pr-i)(18)(Br)](-), the heterometallic Ti15Co6 anion of which contains a Br- ion trapped within a polyoxotitanate shell. This arrangement provides evidence of new host-guest chemistry in this area.