Patent ID: 8889805

Claim:
A carboxylate metal complex represented by formula (C1); (in the formula, M represents a metal atom of group 10 element in the periodic table; X represents a phosphorous atom (P) or an arsenic atom (As); R 1 represents a hydrogen atom or hydrocarbon group having 1 to 30 carbon atoms which may be substituted by one or more functional groups selected from a halogen atom, alkoxy group, aryloxy group, acyloxy group or amino group; R 2 and R 3 independently represent a hydrogen atom, alkoxy group, aryloxy group, acyloxy group, silyl group, amino group or hydrocarbon group having 1 to 30 carbon atoms which may be substituted by one or more functional groups selected from a halogen atom, alkoxy group, aryloxy group, acyloxy group or amino group; R 2 and R 3 may bond to each other to form a ring structure; Y represents divalent hydrocarbon group having 1 to 70 carbon atoms which may be substituted by one or more functional groups selected from a halogen atom, alkoxy group, aryloxy group, acyloxy group or amino group; L represents a neutral electron-donating ligand and n is 0, ½, 1 or 2.