Table 1. Types of hydrogen bonds (H-bonds) formed on different surfaces by 5-FU, 5-FU₁, and 5-FU₂.

	Bond distance (Å)						Total number of H-bonds
	5-FU		5-FU1		5-FU2
MCM-41 surfaces	Donor	Acceptor	Donor	Acceptor	Donor	Acceptor
Plain	2.25	2.30	1.87	2.49,1.77	1.65	1.61	7
NH2	2.80	1.89, 2.22	1.91	1.52, 2.39	1.78	1.50, 2.43	9
CN	2.73	2.02, 2.20	2.65	1.73, 1.60	2.33	1.63, 3.20	9
COOH	2.57, 2.58	2.32, 2.25	1.75	1.55, 1.52	1.80	1.60	9
CH3	–	2.07	–	1.54	–	1.54	3
NH3+	2.20	2.30, 3.10	1.89	1.54, 2.37, 1.75	2.90, 2.89	1.54, 1.92	11
COO–	2.28	2.32	–	–	–	–	2