Table 2. Selected bond lengths (Å) for compounds 1–5.

	1	2	3	4	5
N1–B1	1.423(2)	—	—	1.572(2) a	—
N1–B2	1.430(2)	—	—	—	—
N1–C1	1.497(2)	—	—	—	—
Mg1–N1	—	2.0957(16)	2.1003(16)	2.0334(13)	2.033(5) b
Mg1–N2	—	2.0931(17)	2.0840(16)	2.0361(13)	2.057(4) c
Mg1–N3	—	2.1062(16)	2.0951(16)	2.0825(13)	1.996(6) d
Mg1–O1	—	—	—	1.9714(11)	1.974(4) e
N3–C30	—	1.263(2)	1.271(2)	1.266(2)	1.188(8) f , g

^aN3–B1.

^bMg2–N4 2.046(4).

^cMg2–N4 2.0467(4).

^dMg1–N5.

^eMg2–O2 1.953(4).

^fN(5)–C(30).

^gN6–C79 1.114(7).