Table 2. Key Structural Parameters and Associated Excited State Properties of Molecules 2a, 2b, 2c, and 2d^a.

	state	conformer	r/Å	B-X/Å	∠φ/°	∠τ/°	ES1	fS1	ET1	ΔES1–T1	ESOC
	GS	bent*	1.40		0.1	35.5	4.00	0.44949	3.23	0.77	0.07
	T1	twisted	1.50		79.1	0.5	2.41	0.04050	2.36	0.05	0.05
2a	T1	bent*	1.39		2.3	33.4	3.64	0.10686	2.18	1.36	1.45
	S1	twisted*	1.50		89.8	0.0	2.30	0.00001	2.29	0.01	0.02
	S1	bent	1.50		1.5	24.2	2.82	0.14981	2.61	0.21	0.14
	GS	bent*	1.39	3.19	0.1	39.9	4.13	0.40272	3.24	0.89	0.05
2b	T1	bent*	1.39	2.94	2.1	51.6	3.66	0.13260	2.13	1.53	2.54
	S1	twisted*	1.51	2.98	81.7	61.2	2.46	0.00421	2.45	0.01	0.11
	S1	bent	1.50	3.05	26.2	51.2	2.84	0.11183	2.65	0.19	0.45
	GS	twisted*	1.49	2.15	86.7	24.4	3.65	0.00002	3.12	0.53	0.25
	GS	bent	1.40	2.91	0.2	45.6	3.93	0.23is901	3.22	0.71	0.04
2c	T1	twisted	1.52	2.30	86.6	0.5	2.24	0.00008	2.23	0.01	0.03
	T1	bent*	1.39	2.90	1.3	42.4	3.59	0.07999	2.16	1.43	0.54
	S1	twisted*	1.52	2.31	87.7	1.1	2.21	0.00006	2.20	0.01	0.01
	GS	bent*	1.40	3.23	2.1	51.9	3.78	0.01218	3.24	0.54	0.11
2d	T1	bent*	1.43	3.08	1.0	43.8	2.32	0.00499	2.16	0.16	0.31
	S1	bent*	1.47	3.013	32.6	48.34	2.31	0.00308	2.29	0.02	0.31

^aOnly the stable conformers are shown, and the lowest energy conformer for each state is marked with *. The bond distance r and angles φ and τ are defined in Figure 2. Energies are given in eV and the SOCME are in cm^–1.