Table 6.

Heavy-isotope effects determined in the presence and absence of metal ion catalysts.

catalyst	substrate	18knuc	18klg	18kNB	15kNO2	ref.
30a	HPNP (1)	0.9874b	1.0113		1.0015	[198]
HO− c	HPNP (1)	1.0079b	1.0064		1.0002	[198]
30	HPNP (1)	0.9926d	1.0042d			[200]
H2O	HPNP (1)	1.0182d	1.0021d			[200]
Zn2+ e	UpG	0.986	1.015	1.0007		[197]
HO− f	UpG	0.997	1.0343	0.999		[197]
CuTACNg	EtPNPh				1.0013	[199]
HO−	EtpNP				1.0016	[199]

^apH 7.8 HEPES buffer, 40 °C. ^bObserved values have been corrected for the calculated EIE for deprotonation of HPNP. ^cpH 10.1 CHES buffer, 67 °C. ^dBased on DFT calculation. ^e10 mmol L⁻¹ ZnNO₃, pH 7, 90 °C; ^fpH 12, 90 °C; ^gpH 7.2, 70 °C, ^hethyl p-nitrophenyl phosphate.