Scheme 1: Synthesis of VO(hntdtsc)(HPIP) (1), R1=OH, R2=H, R3=H; VO(hntdtsc)(m-HPIP) (2), R1= H, R2=OH, R3=H; VO(hntdtsc)(p-HPIP) (3), R1=H, R2= H, R3=OH.