title: Self-assembly of oxamidato bridged ester functionalised dirhenium metallastirrups: synthesis, characterisation and cytotoxicity studies.
abstract: A new set of ester functionalised Re(i)-based oxamidato bridged neutral dinuclear metallacycles were synthesised by self-assembly of four components from three building blocks in a facile one-pot reaction via an orthogonal bonding approach. Oxidative addition of oxamide ligands (H2L = N,N'-diphenyloxamide, and N,N'-dibenzyloxamide) to rhenium carbonyl (Re2(CO)10) in the presence of semi-rigid and flexible ditopic pyridyl ligands (L' = o-phenylene diisonicotinate (pdi), ethane diyl di-4-pyridine carboxylate (etdp) and 1,4-butane diyl di-4-pyridine carboxylate (budp)) having ester functionality afforded neutral dirhenium metallacycles of the general formula [(CO)3Re(μ-L)(μ-L')Re(CO)3] (1-5) under solvothermal reaction conditions. The metallacyclic compounds were characterised using elemental analyses, IR, UV-vis and NMR spectroscopic techniques. Structural analyses of 2-5 by single crystal X-ray diffraction methods revealed a stirrup like molecular framework in which two fac-Re(CO)3 units are bridged together by dissymmetrical NO∩ON bis-chelation of oxamide ligands (as a pedestal of stirrups) and further connected by a flexible ditopic tecton (as an arched anchor of stirrups) in an orthogonal fashion. The cytotoxicity activities of dirhenium metallacycles 1-5 were studied in vitro against three different cancer cell lines and normal cells.
authors.affiliation: Department of Chemistry, Pondicherry University, Puducherry, 605014, India.
authors.forename: Buthanapalli
authors.initials: B
authors.lastname: Ramakrishna
authors.forename: R
authors.initials: R
authors.lastname: Nagarajaprakash
authors.forename: V
authors.initials: V
authors.lastname: Veena
authors.forename: N
authors.initials: N
authors.lastname: Sakthivel
authors.forename: Bala
authors.initials: B
authors.lastname: Manimaran
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D060326:Chemistry Techniques, Synthetic; D004952:Esters; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D010072:Oxamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D004952:Esters; D009942:Organometallic Compounds; D012211:Rhenium; D010072:Oxamic Acid; C008728:oxamide