Attached
The focus would be on rhenium complexes which have potential biomedical applications such as
biological imaging and anti-cancer properties. The synthesis and characterization of novel sulfonamide
complexes would be discussed with a special focus on S-N bond distances involving tertiary sulfonamide
linkages. Previous work has paved the way by establishing that near normal Re-N bond distances were
observed in crystal structures containing rhenium complexes bearing dipicolylamine based sulfonamide
ligands. A significant part of drug discovery in the last forty years has been focused on agents to prevent
or treat cancer. Neutral and cationic rhenium complexes providing both hydrophilic as well as
hydrophobic properties bearing the robust tridentate ligand system of biphenyl sulfonyl dipicolylamine
(N(S02bip)dpa) and biphenyl sulfonyl dien (bipS02-dienH) have been synthesized and when coordinated
to the [Re(CO)3]+ core, hold a high potential for the development of metal base anti-cancer drugs. The
obtained S-N bond length is comparable with the S-N bond lengths of 1.6194(11) A for A/(S02pip)dpa
and 1.602(9) A for N-methyltoluene-p-sulfonamide. However that has not depicted by the shortening of
S-N bond length in /V(S02bip)dpa as that of the most common cases.
Specific examples where single crystal diffraction and NMR spectroscopy have worked hand in hand to
identify different isomers of rhenium tricarbonyl complexes bearing iminoether ligands and how
structural characterization of a series of rhenium complexes bearing linear NNN donors paved the way
to prbpose a mechanistic approach towards forming a novel insitu ligand will also be discussed.
