Synthesis, characterization, and structural studies of mercury(II) complexes of new bidentate phosphorus ylide

• Published in: Inorganica Chimica Acta 2010-04, Vol.363 (6), p.1254-1261
• Main Authors: Sabounchei, Seyyed Javad, Samiee, Sepideh, Salehzadeh, Sadegh, Bayat, Mehdi, Nojini, Zabihollah Bolboli, Morales-Morales, David
• Format: Article
• Language: English
• Subjects: Bidentate phosphorus ylide; Crystal structure; Mercury(II) complexes
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2010.01.024

The reaction of Ph 2PCH 2CH 2PPh 2 with BrCH 2C(O)C 6H 4NO 2 affords a mixture of both the mono- and diphosphonium salt simultaneously. The reaction of mercury(II) halides with [Ph 2PCH 2CH 2PPh 2 CHC(O)C 6H 4NO 2] yielded P,P-coordinated complexes. The result of theoretical study showed that the experimentally determined structure of the complex {HgI 2(Ph 2PCH 2CH 2PPh 2CHC(O)C 6H 4NO 2) 2} ( 7) is more stable than its potential geometrical isomers. The reaction of Ph 2PCH 2CH 2PPh 2 (dppe) with BrCH 2C(O)C 6H 4NO 2 (1:1.05 molar ratio) in acetone produces a mixture of the new monophosphonium salt [Ph 2PCH 2CH 2PPh 2CH 2C(O)C 6H 4NO 2]Br ( 1) and the diphosphonium salt [NO 2C 6H 4C(O)CH 2PPh 2CH 2CH 2PPh 2CH 2C(O)C 6H 4NO 2]Br 2 ( 2). Compound 2 was insoluble in acetone and thus easily separated from the solution of 1. Further, by reacting both the mono- and diphosphonium salts with the appropriate bases the bidentate phosphorus ylides, [Ph 2PCH 2CH 2PPh 2 CHC(O)C 6H 4NO 2] ( 3) and [NO 2C 6H 4C(O)CH PPh 2CH 2CH 2PPh 2 CHC(O)C 6H 4NO 2] ( 4) were obtained. The reaction of ligand 3 with mercury(II) halides in dry methanol leads to the formation of the P,P-coordinated monomeric complexes {HgX 2(Ph 2PCH 2CH 2PPh 2CHC(O)C 6H 4NO 2) 2} [X = Cl ( 5), Br ( 6), I ( 7)]. The structure of complex 7 being unequivocally determined by single crystal X-ray diffraction techniques. Characterization of these species was also performed by elemental analysis, IR spectroscopy and 1H, 31P, and 13C NMR techniques. These analyses being consistent with a 2:1 stoichiometry ylide/Hg(II) for compounds 5 through 7. Results obtained from theoretical studies are also consistent with a product in which two ylides are coordinated to the Hg(II) center through their phosphine groups, being this product the most stable among all the possible products.