A novel strategy to construct Janus metallamacrocycles with both a Ru–arene face and an imidazolium face. Issue 46 (13th November 2017)

• Record Type: Journal Article
• Authors: Li, Ji; Zhang, Peipei; Xu, Yan; Su, Zhi; Qian, Yong; Li, Shunli; Yu, Tao; Sadler, Peter J.; Liu, Hong-Ke
• Is Part Of: Dalton transactions. Volume 46:Issue 46(2017)
• Page Start: 16205
• Page End: 16215
• Publication Date: 2017-11-13
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt03374e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : We report a novel strategy to synthesize Janus metallocyclic Ru–arene complexes with both a Ru–arene face and a didentate imidazolium face, which possess unusual structures and properties. Abstract : The bottom-up construction of highly functional metallamacrocycles from simple building blocks is a challenge of much current interest. We have used solvothermal reactions of a bifunctional p -bitmb ligand with [Ru(arene)X2 ]2 in CH2 Cl2 or CH2 Br2 to generate the novel mononuclear metallamacrocyclic [RuX(arene)L2 CH2 ]X3 complexes1–3 (1, arene = p -cym, X = Cl;2, arene = bip, X = Cl;3, arene = p -cym, X = Br), which were characterized by various techniques. These complexes are "bowl-like" and have two faces: one coordinative Ru centre (arene)Ru( N, N )X bridged by L (L = 1, 4-bis(imidazol-1-ylmethyl)-2, 3, 5, 6-tetramethylbenzene, p -bitmb) to a dipositive bis-imidazolinium centre. Cl − or Br − anions can be trapped inside the cavity of the "bowl-like" structure, forming H-bonds with the backbone. Experimental (NMR and ESI-MS) and computational (DFT calculations) studies show that the source of the bridging –CH2 – group is the dihalogenated solvent (CH2 Cl2 or CH2 Br2 ) that links the two arms of an initially formed non-cyclic complex (arene)RuX2 L2 by a mechanism of nucleophilic substitution. Optimization of the reaction conditions afforded the macrocyclic complexes in almost quantitative yields. The applications of these complexes as anti-proliferative agents towards cancer cells and for selective anion sensing have been explored.