Abstract: A neutral complex of a cyclic silane characterized in being represented by the general formula [Y]1[SimZ2m-aHa]. (In the formula: Y is at least one kind of coordination compound selected from a group consisting of (1) compounds represented as X1R1n. (when X1 is P, P?O or N, n=3 and each R1 represents a substituted or unsubstituted alkyl group or aryl group and R1s are the same or different; when X1 is S, S?O or O, n=2 and each R1 represents the same group as described above and R1s are the same or different; and the number of amino groups in X1R1n is 0 or 1), and (2) at least one heterocyclic compound selected from the group consisting of substituted or unsubstituted N—, O—, S —or P— containing heterocyclic compounds that have an unshared electron pair in the ring (the number of amino groups in the heterocyclic compound is 0 or 1), each Z represents a halogen atom of any of Cl, Br, I and F and Zs are the same or different, l is 1 or 2, m is 3 to 8, and a is 0 to m.

Abstract: A neutral complex of a cyclic silane characterized in being represented by the general formula [Y]1[SimZ2m-aHa]. (In the formula: Y is at least one kind of coordination compound selected from a group consisting of (1) compounds represented as X1R1n. (when X1 is P, P?O or N, n=3 and each R1 represents a substituted or unsubstituted alkyl group or aryl group and R1s are the same or different; when X1 is S, S?O or O, n=2 and each R1 represents the same group as described above and R1s are the same or different; and the number of amino groups in X1R1n is 0 or 1), and (2) at least one heterocyclic compound selected from the group consisting of substituted or unsubstituted N-, O-, S- or P-containing heterocyclic compounds that have an unshared electron pair in the ring (the number of amino groups in the heterocyclic compound is 0 or 1), each Z represents a halogen atom of any of Cl, Br, I and F and Zs are the same or different, l is 1 or 2, m is 3 to 8, and a is 0 to m.