Design of alkyl- and haloalkyl complexes of dimethylplatinum(IV) via oxidative addition: Reactivity, characterization and crystal structures

作者：Momeni Badri Z^*; Hadi Saba; Biglari Abbas

来源：Inorganica Chimica Acta, 2017, 455: 262-270.

DOI：10.1016/j.ica.2016.10.029

• Platinum
• Oxidative addition
• Dihaloalkane
• NMR
• Crystal structure

Dimethylplatinum(II) complexes [PtMe2(NN)] {NN = 5,5'-Me(2)bpy (5,5'-dimethyl-2,2'-bipyridine; phen (1,10-phenanthroline)) were reacted with benzyl bromide to yield the organoplatinum(IV) complexes [PtMe2(PhCH2)Br(NN)] {NN = 5,5'-Me(2)bpy (1), phen (2)). On the basis of NMR data, the Pt(IV) products of 1-2 contain almost exclusively the trans isomer and small traces of the cis isomers are also observed. Oxidative addition of dimethylplatinum(II) complexes [PtMe2(NN)] with dihaloalkanes CH2Cl2 and Br (CH2)(4)Br have also been investigated. The reactions of complexes [PtMe2(NN)] {NN = 4,4'-Me(2)bpy (4,4'-dimethy1-2,2'-bipyridine); 5,5'-Me(2)bpy; phen} with dihaloalkanes CH2Cl2 and Br(CH2)(4)Br resulted in the formation of the new organoplatinum(IV) complexes [PtMe2(CH2Cl)Cl(NN)] {NN = 4,4'-Me(2)bpy (3); 5,5'-Me(2)bpy (4)) and [PtMe2{(CH2)(4)Br}Br(NN)] {NN = 4,4'-Me(2)bpy (5); 5,5'-Me(2)bpy (6); phen (7)), respectively. The products have been characterized by elemental analysis,H-1,C-13, HH-COSY and DEPT-135 NMR spectroscopy. On the basis of NMR data, in the case of CH2Cl2, the platinum(IV) products of the reaction contain a mixture of cis and trans isomers, while small traces of the cis isomer are observed in the case of Br(CH2)(4)Br. NMR data indicates that the trans influence of bpy, 4,4'-Me(2)bpy and 5,5'-Me(2)bpy is the same. The crystal structures of [PtMe2(CH2Cl)Cl(4,4'-Me(2)bpy)] and [PtMe2{(CH2)(4)Br}Br(4,4'-Me(2)bpy)] reveal a slightly distorted octahedral geometry of the platinum(IV) metal center with haloalkyl group trans to halide. The haloallcyl chains of CH2Cl and (CH2)(4)Br units are twisted respect to the 4,4'-Me(2)bpy ligand with a syn arrangement. Therefore, the steric hindrance can be partially relieved.

• 出版日期2017-1-30