The first examples of multiply bonded dirhenium(iii,ii) paramagnetic complexes containing nitrobenzoate ligands: spectroscopic, structural, cytotoxicity and computational studies.
4-Nitrobenzoic acid, 3-nitrobenzoic acid and 4'-nitro[1,1'-biphenyl]-4-carboxylic acid react with the multiply bonded paramagnetic dirhenium(iii,ii) complex Re2(μ-O2CCH3)Cl4(μ-Ph2PCH2PPh2)2(1) in refluxing ethanol to afford the paramagnetic substitution products of the type Re2(μ-L)Cl4(μ-Ph2PCH2PPh2)2, where L represents the nitrobenzoate ligands [L = 4-nitrobenzoate, 2; 3-nitrobenzoate, 3; 4'-nitro[1,1'-biphenyl]-4-carboxylate, 4]. These are the first examples of paramagnetic dirhenium complexes containing nitrobenzoate ligands. The spectral (UV-vis, IR, and EPR) and electrochemical properties of the complexes are described. The identity of 4 has been established by single-crystal X-ray structure determination (Re-Re distance of 2.2967(4) Å). The electronic structures of the complexes were scrutinized by density functional theory (DFT) calculations. X-band EPR spectral measurements along with the DFT analysis show that the unpaired electron resides in the metal-metal δ* antibonding orbital. The complexes were also screened in vitro for their antiproliferative properties against the human breast cancer cell line MCF-7 by the MTT assay. Flow cytometry analysis showed that the complexes arrested the sub-G0/G1 phase.
Department of Chemistry, University of Kalyani, Kalyani, Nadia 741235, WB, India. icskc@klyuniv.ac.in.
Suman
S
Mallick
Mrinal Kanti
MK
Ghosh
Suman
S
Mandal
Vinayak
V
Rane
Ramakant
R
Kadam
Annesha
A
Chatterjee
Arindam
A
Bhattacharyya
Swarup
S
Chattopadhyay
D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D008024:Ligands; D061986:MCF-7 Cells; D008280:Magnetics; D018613:Microscopy, Confocal; D008968:Molecular Conformation; D009579:Nitrobenzoates / Q000737:chemistry*; D011789:Quantum Theory; D012211:Rhenium / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
D056831:Coordination Complexes; D008024:Ligands; D009579:Nitrobenzoates; D012211:Rhenium