Table 1. Selected bond lengths and angles (Å, °).

Compound (I)		Compound (II)		Compound (III)
Zn1—Cl1	2.215 (2)	Zn1—Br1	2.3575 (9)	Zn1—I1	2.5534 (8)
Zn1—Cl2	2.211 (2)	Zn1—Br2	2.3472 (10)	Zn1—I2	2.5475 (9)
Zn1—O1	1.991 (5)	Zn1—O1	1.975 (4)	Zn1—O1	1.974 (4)
Zn1—O2	1.959 (5)	Zn1—O2	1.989 (4)	Zn1—O2	1.995 (4)
Cl1—Zn1—Cl2	117.80 (9)	Br1—Zn1—Br2	123.45 (4)	I1—Zn1—I2	122.34 (3)
O1—Zn1—O2	99.4 (2)	O1—Zn1—O2	103.10 (16)	O1—Zn1—O2	104.12 (19)