Synthesis, characterization and biological aspects of novel five-coordinated dimeric-Cu(II) systems

Figures & data

Scheme 1 Synthesized Schiff bases.

Table I.  Biocidal activity data of compounds.

	Zone of Inhibition in mm
Compounds	E. Coli	B. Subtilis	S. aureus	S. typhi	B.cereus	S. marcesens
Cantrol	11	11	10	11	11	11
Cu(NO3)2·3H2O	14	17	19	18	19	18
LH(Cpf. HCl)	28	34	40	32	31	37
Std. 1 (Ofl. HCl)	30	34	39	33	30	32
Std. 2 (Lef. HCl)	33	36	38	29	28	34
Std. 3 (flucanozole)	15	19	11	12	11	12
A^1	12	15	25	18	19	22
A^2	17	11	12	12	11	16
A^3	13	14	16	14	15	19
A^4	19	12	11	16	12	14
A^5	11	11	11	11	12	19
A^6	13	14	13	14	15	14
A^7	17	11	12	16	15	17
A^8	14	14	15	11	11	19
I	36	25	37	33	26	35
II	42	41	37	27	28	38
III	39	39	41	28	27	36
IV	32	30	31	26	25	30
V	41	40	36	31	31	38
VI	41	39	39	28	29	43
VII	40	40	39	28	33	35
VIII	42	38	37	30	25	52

short-legendScheme 2

Table II.  Infrared spectral data of complexes.

Compounds	ν (C = O) cm^− 1 Pyridone	ν (COO)asy cm^− 1	ν (COO)sym cm^− 1	Δν cm^− 1	ν (C–Cl) cm^− 1	ν (C = N) cm^− 1 Azo methine	ν (C = N) cm^− 1 Ring	ν (M–N) cm^− 1	ν (M–O) cm^− 1	ν (M–S) cm^− 1
I	1632	1583	1381	202	1111	–	1612	539	504	–
II	1628	1581	1376	205	1147	1666	1620	545	511	–
III	1626	1589	1381	208	1128	1575	–	520	515	420
IV	1632	1578	1371	207	1179	1602	–	540	505	–
V	1627	1580	1370	210	1146	1605	–	542	511	–
VI	1629	1588	1382	206	1145	1570	–	541	514	–
VII	1631	1578	1377	201	1102	1575	–	540	510	–
VIII	1633	1584	1383	201	1111	1574	–	537	502	–

Table III.  Electronic spectral data of complexes.

Compounds	d-d transition in solid state cm^− 1	λmax in DMSO	μeff B.M.
		d-d transition nm(cm^− 1)
I	12770	783 (12771)	1.87
II	13765	726 (13774)	2.10
III	16980	589 (16977)	1.90
IV	13150	760 (13157)	1.76
V	14180	705 (14184)	1.84
VI	13100	762 (13123)	1.99
VII	14550	688 (14534)	1.94
VIII	14280	700 (14285)	1.80

Table IV.  Thermal data of complexes.

		TGA		DSC°C
Compounds	Process	Temperature range°C	Mass loss % Found/Calc.	Endo peaks	Melting point
I	[Cu2(L)2(A^1)2(pip)]·5H2O → Cu2(L)2(A^1)2(pip)]+5H2O	30–110	7.32/7.46	128.59	260
	[Cu2(L)2(A^1)2(pip)] → [Cu2(L)2(A^1)2]+ pip	170–215	7.10/6.99
	[Cu2(L)2(A^1)2] → [Cu2(A^1)2]+2L	245–480	46.78/46.67
	[Cu2(A^1)2] → 2Cu + 2A^1	520–660	28.21/28.40
II	[Cu2(L)2(A^2)2(pip)]·5H2O → [Cu2(L)2(A^2)2(pip)]+5H2O	30–105	7.31/7.33	114.61	293
	[Cu2(L)2(A^2)2(pip)] → [Cu2(L)2(A^2)2]+ pip	175–210	6.79/6.87
	[Cu2(L)2(A^2)2] → [Cu2(A^2)2]+2L	250–490	45.73/45.83
	[Cu2(A^2)2] → 2Cu + 2A^2	510–670	29.76/29.70
III	[Cu2(L)2(A^3)2(pip)]·5H2O → [Cu2(L)2(A^3)2(pip)]+5H2O	26–105	7.30/7.27	125.63	349
	[Cu2(L)2(A^3)2(pip)] → [Cu2(L)2(A^3)2]+ pip	150–205	6.94/6.81
	[Cu2(L)2(A^3)2] → [Cu2(A^3)2]+2L	240–475	45.42/45.45
	[Cu2(A^3)2] → 2Cu + 2A^3	510–650	30.29/30.27
IV	[Cu2(L)2(A^4)2(pip)]·5H2O → [Cu2(L)2(A^4)2(pip)]+5H2O	24–110	5.90/5.87	110.02	273
	[Cu2(L)2(A^4)2(pip)] → [Cu2(L)2(A^4)2]+ pip	180–220	5.69/5.50
	[Cu2(L)2(A^4)2] → [Cu2(A^4)2]+2L	240–480	36.85/36.72
	[Cu2(A^4)2] → 2Cu + 2A^4	510–670	43.54/43.67
V	[Cu2(L)2(A^5)2(pip)]·5H2O → [Cu2(L)2(A^5)2(pip)]+5H2O	32–105	6.72/6.74	124.24	273
	[Cu2(L)2(A^5)2(pip)] → [Cu2(L)2(A^5)2]+ pip	165–200	6.37/6.31
	[Cu2(L)2(A^5)2] → [Cu2(A^5)2]+2L	220–460	42.18/42.11
	[Cu2(A^5)2] → 2Cu + 2A^5	490–640	35.45/35.39
VI	[Cu2(L)2(A^6)2(pip)]·5H2O → [Cu2(L)2(A^6)2(pip)]+5H2O	45–110	5.68/5.80	92.72	284
	[Cu2(L)2(A^6)2(pip)] → [Cu2(L)2(A^6)2]+ pip	170–220	5.38/5.43
	[Cu2(L)2(A^6)2] → [Cu2(A^6)2]+2L	250–490	36.23/36.24
	[Cu2(A^6)2] → 2Cu + 2A^6	520–700	44.31/44.40
VII	[Cu2(L)2(A^7)2(pip)]·5H2O → [Cu2(L)2(A^7)2(pip)]+5H2O	36–105	5.20/5.22	115.61	288
	[Cu2(L)2(A^7)2(pip)] → [Cu2(L)2(A^7)2]+ pip	140–200	4.91/4.89
	[Cu2(L)2(A^7)2] → [Cu2(A^7)2]+2L	240–480	32.87/32.67
	[Cu2(A^7)2] → 2Cu + 2A^7	515–710	49.93/49.88
VIII	[Cu2(L)2(A^8)2(pip)]·5H2O → [Cu2(L)2(A^8)2(pip)]+5H2O	45–110	6.52/6.43	118.50	251
	[Cu2(L)2(A^8)2(pip)] → [Cu2(L)2(A^8)2]+ pip	175–205	6.07/6.02
	[Cu2(L)2(A^8)2] → [Cu2(A^1)2]+2L	245–480	39.96/40.18
	[Cu2(A^8)2] → 2Cu + 2A^8	510–670	38.20/38.36

Figure 1 TGA of [Cu₂(Cip)₂(bipym)₂(pip)]·5H₂O.

Table V.  IC₅₀ values of copper complexes.

Compounds	IC50 (μM)	References
I	0.058	This work
II	0.055	This work
III	0.052	This work
IV	0.048	This work
V	0.056	This work
VI	0.055	This work
VII	0.052	This work
VIII	0.090	This work
[Cu2(L^4)2(OCH3)2(NH3)2]	0.103	17
[Cu2(L^4)2(OCH3)2(DMSO)2]	0.059	17
[Cu(L^1)2(NH3)2].MeOH	0.244	17
[Cu(L^2)2(DMSO)2]	0.188	57
[Cu(L^4)2(py)2]	0.146	56
[Cu(stz)2(py)3Cl]	1.310	58
[Cu(stz)2(Him)2].MeOH	0.664	59
[Cu(stz)2(4-mHim)2]	0.586	60
Cu2Zn2SOD	0.006	56

Table VI.  DNA interaction data with the complexes.

Compound	DNA μgm	Compound λmax nm	A^n λmax nm	L λmax nm	Cu(II) λmax nm
I	0	277	260.4	260.0	260.0
[Cu2(L)2(A^1)2(pip)]·5H2O	3	261	259.6	259.2	258.0
	5	259	258.6	258.8	257.2
	7	258	245.0	247.4	256.4
II	0	273	260.6	260.0	260.0
[Cu2(L)2(A^2)2(pip)]·5H2O	3	262	258.4	259.2	258.0
	5	260	258.0	258.8	257.2
	7	259	249.4	247.4	256.4
III	0	273	260.0	260.0	260.0
[Cu2(L)2(A^3)2(pip)]·5H2O	3	261	258.2	259.2	258.0
	5	257	257.8	258.8	257.2
	7	256	246.6	247.4	256.4
IV	0	270	263.0	260.0	260.0
[Cu2(L)2(A^4)2(pip)]·5H2O	3	259	259.2	259.2	258.0
	5	258	258.2	258.8	257.2
	7	257	244.2	247.4	256.4
V	0	273	265.2	260.0	260.0
[Cu2(L)2(A^5)2(pip)]·5H2O	3	263	259.2	259.2	258.0
	5	260	258.2	258.8	257.2
	7	258	246.6	247.4	256.4
VI	0	273	261.7	260.0	260.0
[Cu2(L)2(A^6)2(pip)]·5H2O	3	264	258.8	259.2	258.0
	5	262	258.0	258.8	257.2
	7	259	244.6	247.4	256.4
VII	0	275	259.0	260.0	260.0
[Cu2(L)2(A^7)2(pip)]·5H2O	3	263	258.4	259.2	258.0
	5	261	258.0	258.8	257.2
	7	258	245.4	247.4	256.4
VIII	0	270	260.3	260.0	260.0
[Cu2(L)2(A^8)2(pip)]·5H2O	3	262	259.4	259.2	258.0
	5	259	258.4	258.8	257.2
	7	258	247.4	247.4	256.4

Figure 2 Absorption spectra of complex [Cu₂(L)₂(A¹)₂(pip)]·5H₂O in absence and presence of [DNA].

Figure 3 Electropheresis of pBR 322 after incubation with different agents. (A) Lane 1: pBR322 (control), lane 2: pBR322 + I, lane 3: pBR322+ II, lane 4: pBR322+ III, lane 5: pBR322+ IV, lane 6: pBR322 + V, lane 7: pBR322+ VI, lane 8: pBR322+ VII, lane 9: pBR322+ VIII (B) Lane 1: pBR322+ Cu(II), lane 2: pBR322 + A¹, lane 3: pBR322 + A², lane 4: pBR322 + A³, lane 5: pBR322 + A⁴, lane 6: pBR322 + A⁵, lane 7: pBR322 + A⁶, lane 8: pBR322 + A⁷, lane 9: pBR322 + A⁸.

Table ViI.  cleavage Of Pbr322 Dna.

	DNA %			DNA %
Compounds	SC	OC	Compounds	SC	OC
Control	100.0	00.00	Cu(II)	72.15	27.85
A^1	54.57	45.43	I	36.63	63.37
A^2	75.00	25.00	II	71.19	28.81
A^3	48.17	51.83	III	45.05	54.95
A^4	84.95	15.05	IV	36.37	63.63
A^5	47.35	52.65	V	34.31	65.69
A^6	83.94	16.06	VI	58.29	41.71
A^7	81.12	18.88	VII	69.13	30.87
A^8	86.99	13.01	VIII	44.62	55.38