The Use of 7,7′,8,8′-Tetracyanoquinodimethane for the Spectrophotometric Determination of Some Primary Amines Application to Real Water Samples

Table 8

Association constants of the TCNQ-amine complexes.

Primary amine	Volume (mL)	Conc. (M)	Absorbance		𝛼	Kc average (L·mol^−1)
			As	Am
	0.1		0.094	0.165	0.430
Aniline	0.3	1×10^−3	0.213	0.345	0.382	2.741×10^5
	0.4		0.373	0.485	0.229
	0.05		0.070	0.168	0.583
p-Aminophenol	0.2	1×10^−3	0.335	0.466	0.281	1.701×10^6
	0.4		0.555	0.599	0.073
	0.03		0.029	0.043	0.326
Benzidine	0.1	1×10^−4	0.037	0.073	0.493	1.844×10^6
	0.2		0.057	0.105	0.457
	0.05		0.037	0.062	0.403
Ethylamine	0.2	1×10^−3	0.043	0.168	0.744	8.78×10^4
	0.4		0.163	0.240	0.320
	0.1		0.012	0.097	0.876
1,2-Diaminopropane	0.3	1×10^−3	0.154	0.195	0.210	8.208×10^5
	0.4		0.188	0.212	0.113