Table 2.

Electron density at bond critical points found in the keto-enol fragment of molecules 1a, 1b, 1c, 2a, 2b, and 3

ρ (eÅ−3)	H1–O2	O2–C3	C3–C4	C4–C5	C5–O6	O6–H1
1a	0.419	2.530	1.930	2.171	2.137	2.136
2a	n/a	2.700	1.834	2.236	1.988	2.485
1b	2.102	2.130	2.149	1.946	2.545	0.446
2b	2.475	1.983	2.226	1.823	2.728	n/a
1c	1.240	2.324	2.050	2.062	2.360	1.160
3	1.084	2.132	2.057	2.026	2.354	0.861
Experiment	0.89  (3)	2.44  (8)	2.17  (4)	2.04  (4)	2.54  (8)	0.76  (3)

The experimental value is included for comparison (14). The atom numbering scheme corresponds to 1a.