A compound represented by the formula (1) is provided: wherein A1 represents an oxygen atom, a sulfur atom, —NR5— or —PR5—; at least one A1 is —NR5— or —PR5—; R1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylsulfenyl group, a cycloalkylsulfenyl group, an arylsulfenyl group or a disubstituted amino group; R2 and R3 represent an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkylsulfenyl group, a cycloalkylsulfenyl group, an arylsulfenyl group, a monovalent heterocyclic group, a halogen atom or a disubstituted amino group; R4 represents a hydrogen atom, —C(R6)3, —OR7, —N(R7)2 or —Si(R7)3; m represents an integer of 0 to 3; and n represents an integer of 0 to 4.