Table 2. B–S bond lengths (Å) and Wiberg bond index values for optimized structures of sulfide-coordinated compounds^a.

Compound	B–S bond lengths/Å		Wiberg bond index
cis-1a	B1–S1	2.233	0.537
	B2–S2	2.232	0.539
cis-1b	B1–S1	2.296	0.484
	B2–S2	2.296	0.484
trans-1a	B1–S1	2.284	0.504
	B2–S2	2.285	0.503
trans-1b	B1–S1	2.382	0.429
	B2–S2	2.347	0.452
cis-5	B1–S1	2.145	0.625
	B2–S2	2.145	0.625
A	B1–S1	2.053	0.714

^aNBO calculations were conducted at the B3LYP-D3/6-311+G(d,p) level of theory.