Mn(II) complexes of phenylenediamine based macrocyclic ligands as T-MRI contrast agents.

The Mn(II) complexes are emerging as alternative T-MRI contrast agents (CAs) to the currently available Gd-based CAs. The complexes [Mn(L1)] 1 and [Mn(L2)] 2 of o-phenylenediamine based macrocyclic ligands are reported as T-CAs for MRI applications. The high spin state of the Mn(II) complexes (S = 5/2) is confirmed by EPR spectra.

Copper(II) complexes of tripodal ligand scaffold (NO) as functional models for phenoxazinone synthase.

The copper(II) complexes [Cu(L)NO] (1-9) of newer NO ligands (L1-L9) have been synthesized and characterized. The molecular structure of 1, 4, and 7 exhibited nearly a perfect square pyramidal geometry (τ, 0.04-0.