Table 1. Selected bond lengths (Å) for compounds (1)–(4).

Compound	M—N1	S1—O4	S1—O5	S1—O6
(1)	2.227 (3)	1.462 (2)	1.4650 (17)	1.484 (2)
(2)	2.112 (3)	1.462 (3)	1.4618 (17)	1.488 (2)
(3)	2.066 (2)	1.464 (2)	1.4588 (14)	1.4895 (19)
(4)	2.0924 (19)	1.4641 (19)	1.4596 (13)	1.4886 (18)