Table 1.

Photolysis (5 mW LED at 365 nm) of alkyl-Cbls in phosphate buffered saline.

	ß-axial Substituent	K OW a	k (s−1)b	Φc
3	methyl	1.09	0.10 ± 0.01	0.35 ± 0.02
4	ethyl	1.33	0.13 ± 0.02	0.44 ± 0.05
5	propyl	1.75	0.087 ± 0.006	0.31 ± 0.02
6	isobutyl	2.08	0.084 ± 0.007	0.29 ± 0.02
7	decyl	4.67	0.04 ± 0.02	0.14 ± 0.06
8	cyclopropyl	1.25	0.026 ± 0.003	0.09 ± 0.01
9	cyclopropylmethyl	1.58	0.099 ± 0.004	0.34 ± 0.01
10	cyclobutyl	1.67	0.064 ± 0.006	0.22 ± 0.02
11	cyclobutylmethyl	2.00	0.083 ± 0.006	0.29 ± 0.01
12	cyclohexylmethyl	2.83	0.045 ± 0.004	0.16 ± 0.01
13	1-aminopropyl	0.17	0.079 ± 0.002	0.27 ± 0.01
14	1-carboxyethyl	0.35	0.10 ± 0.01	0.34 ± 0.05
15	1-amino-1-carboxypropyl	-0.41	0.066 ± 0.005	0.23 ± 0.02
16	1-methoxy-1-oxopentyl	1.44	0.074 ± 0.008	0.26 ± 0.03
17	1-carboxypentyl	1.60	0.07 ± 0.01	0.23 ± 0.04
18	1-amino-1-oxohexyl	0.95	0.07 ± 0.01	0.23 ± 0.04

^aThe octanol water partition coefficient was calculated using ChemDraw 20.0.

^bPhotolysis rate from the average of three trials per conjugate.

^cThe quantum yields were calculated using methyl-Cbl as the actinometer.³⁸