Table 3. Comparison of selected (X-ray and DFT) geometric data (Å, °).

Bonds/angles	X-ray	B3LYP/6–311G(d,p)
O1—C3	1.3587 (14)	1.38948
O1—H1O a	0.82	0.97611
N1—C9	1.3865 (16)	1.39921
N1—C1	1.4529 (17)	1.47118
N1—H1N	0.870 (15)	0.90721
C1—N2	1.4745 (16)	1.47531
C1—C2	1.5074 (17)	1.51309
O2—C4	1.3677 (15)	1.40231
O2—C8	1.4088 (17)	1.45201
N2—C11	1.4124 (16)	1.39016
N2—H2N	0.864 (15)	0.90717
C3—O1—H1O a	109.5	109.04
C9—N1—C1	116.86 (10)	117.19
C9—N1—H1N	115.4 (10)	116.29
C1—N1—H1N	113.3 (10)	114.01
N1—C1—N2	106.56 (10)	106.87
N1—C1—C2	109.17 (10)	110.78
N2—C1—C2	111.38 (10)	110.82
N1—C1—H1a	109.9	110.12
N2—C1—H1a	109.9	109.09

Note: (a) These four entries were not refined, as they each include a constrained H atom.