Selected bond lengths (Å) of compounds 2–5. DFT optimized values are shown in square brackets.

	P1–P2/P1′	Ga1–P1	Ga2–P2/P1′	P1–C59
2a	2.0381(5) [2.040]	2.3131(3) [2.332]	2.3131(3) [2.334]	—
3a	2.1871(8)/2.1835(8) [2.158]	2.3328(7)/2.3433(6) [2.325]	2.2747(6)/2.2695(7) [2.280]	1.862(2)/1.864(2) [1.852]
4a	2.142(8) [2.130]	2.3479(13) [2.358]	2.3456(10) [2.354]	1.823(3) [1.816]
5a	2.2227(14)	2.3655(16)	2.3466(16)	1.838(4)
2b	2.0282(8) [2.040]	2.3120(4) [2.333]	2.3120(4) [2.333]	—
3b	2.1623(5) [2.158]	2.3205(4) [2.327]	2.2664(4) [2.280]	1.8570(13) [1.852]
4b	2.1336(7) [2.133]	2.3591(8) [2.359]	2.3522(7) [2.357]	1.8262(19) [1.817]
5b	2.223(3)	2.367(3)	2.339(3)	1.829(8)