Synthesis, Characterization, and Thermal and Antimicrobial Activities of Some Novel Organotin(IV): Purine Base Complexes

Table 5

Kinetic parameters for the thermal decomposition of theophylline and theobromine complexes.

Complex	Step number	Temp./K	Coats-Redfern method		Horowitz-Metzger method		DTA
			𝐸𝑎/kJ mol^−1	Δ𝑆^# (JK^−1 mol^−1)	𝐸𝑎/kJ mol^−1	Δ𝑆^# (JK^−1 mol^−1)	Thermal effect	Δ𝐻 (Jg^−1)
(C6H5CH2)3Sn(L^1)	1	483–673	51.09	9.41	54.23	10.46	Exo.	−20.42
	2	893–1003	306.35	37.62	310.17	38.01	Endo.	94.46
(p-ClC6H4CH2)3Sn(L^1)	1	443–633	40.30	8.50	41.84	8.81	Exo.	−17.46
	2	873–973	218.82	27.42	243.23	29.82	Endo.	93.26
(C6H5CH2)2Sn(L^1)Cl	1	513–663	63.82	12.00	65.62	12.33	Exo.	−22.10
	2	703–773	191.54	32.06	211.40	33.26	Exo.	−89.99
	3	893–973	366.98	45.41	353.53	44.3	Endo.	90.42
(p-ClC6H4CH2)2Sn(L^1)Cl	1	483–673	54.70	10.54	55.23	10.67	Exo.	−21.69
	2	723–793	255.29	39.42	238.49	37.64	Exo.	−92.46
	3	873–973	382.94	47.45	380.48	47.85	Endo.	92.91
(C6H5CH2)3Sn(L^2)Cl	1	473–653	38.29	6.97	40.46	7.95	Exo.	−30.46
	2	723–813	87.03	12.06	95.34	13.83	Exo.	−52.49
	3	893–1003	208.12	24.10	217.31	26.22	Endo.	111.12
(p-ClC6H4CH2)3Sn(L^2)Cl	1	423–623	31.91	6.20	34.91	7.41	Exo.	−29.62
	2	703–753	255.29	41.62	250.21	40.69	Exo.	−51.62
	3	873–973	239.33	30.41	250.95	31.89	Endo.	113.42
(C6H5CH2)2Sn(L^2)Cl2	1	493–653	57.44	11.20	58.55	11.35	Exo.	−29.94
	2	703–773	281.57	43.69	274.33	43.44	Exo.	−51.60
	3	873–993	176.32	21.42	178.57	21.57	Endo.	110.21
(p-ClC6H4CH2)2Sn(L^2)Cl2	1	473–653	54.44	7.84	56.45	8.26	Exo.	−31.06
	2	723–793	191.47	29.47	192.18	29.71	Exo.	−52.06
	3	873–973	237.53	29.01	243.28	29.99	Endo.	112.26