Table 1.

Uptake of O₂ by the Co(II)–l-α-amino acid–imidazole systems (duration time of uptake, final value of pH, number of mmoles of O₂ bound, percentage of reversibility)

Amac	Co(II): amac:Himid (mmole ratio)	Time (min)	pH	mmoles O2	% revers
Alanine	0.3: 0.15:0.3	90	9.882	0.0515	30.33
	0.3:0.225:0.3	105	9.557	0.0559	31.25
	0.3:0.3:0.3	210	9.751	0.0918	31.80
	0.3:0.375:0.3	215	9.629	0.0936	46.76
	0.3:0.5:0.3	215	9.562	0.1193	57.71
	0.3:0.6:0.3	270	9.603	0.1343	49.68
	0.3:0.75:0.3	195	9.418	0.1457	45.56
	0.3:0.9:0.3	270	9.422	0.1661	46.65
	0.3:1.05:0.3	200	9.276	0.1690	48.97
	0.3:1.2:0.3	120	9.247	0.1704	57.72
Asparagine	0.3:0.15:0.3	210	9.498	0.0352	43.37
	0.3:0.225:0.3	150	9.752	0.0567	45.04
	0.3:0.3:0.3	270	9.634	0.0600	44.37
	0.3:0.375:0.3	190	9.656	0.0936	49.77
	0.3:0.45:0.3	150	9.543	0.0901	53.55
	0.3:0.6:0.3	120	9.152	0.1219	60.78
	0.3:0.75:0.3	120	8.919	0.1237	57.84
	0.3:0.9:0.3	200	9.022	0.1304	65.27
	0.3:1.2:0.3	180	8.616	0.1275	67.67
Histidine	0.3:0.15:0.3	90	9.668	0.0373	51.16
	0.3:0.225:0.3	70	9.687	0.0565	52.85
	0.3:0.3:0.3	150	9.535	0.0755	72.99
	0.3:0.375:0.3	70	9.412	0.0932	68.98
	0.3:0.45:0.3	150	9.732	0.1123	69.81
	0.3:0.6:0.3	90	9.193	0.1496	82.63
	0.3:0.75:0.3	105	9.526	0.1513	86.69
	0.3:0.9:0.3	90	9.345	0.1502	85.06
	0.3:1.2:0.3	90	9.234	0.1507	84.81