Effect of copper-sulphur bond on the DNA photo-cleavage activity of 2-(methylthio)ethylpyridine-2-carbaldimine copper(II) complexes

Tarkeshwar Gupta, Ashis K. Patra, Shanta Dhar, Munirathinam Nethaji, Akhil R. Chakravarty

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The binding and photo-induced DNA cleavage activity of a binary complex [CuL2](ClO4)2 (1) and the in situ generated ternary complexes [CuLB](ClO4)2 from 1 (B: 1,10-phenanthroline, phen, 2; dipyrido[3,2-d: 2′,3′-f]quinoxaline, dpq, 3) are studied, where L is a N2S-donor tridentate Schiff base 2-(methylthio)ethylpyridine-2-carbaldimine. Complex 1, structurally characterized by X-ray diffraction study, has six-coordinate meridional geometry snowing CuN4S2 coordination. The Cu-N bond lengths are in the range of 1·968(3) to 2·158(4) Å. The Cu-S bond lengths of 2-599(2) and 2-705(2) Å are significantly long indicating weak covalent interaction between copper and sulphur atoms. The thiomethyl groups are cis to each other giving S-Cu-S angle of 75-82(5)°. The Cu-N(pyridyl) bond distances are longer than the Cu-N(imine) bonds. The complexes are redox active and display a quasi-reversible cyclic voltammetric response assignable to the Cu(II)/Cu(I) couple near 0-0 V vs SCE in DMF-Tris buffer (1:4 ν/ν) using 0·1 M KCl as supporting electrolyte. Electronic spectra of the complexes show a d-d band in the range 630 to 700 nm in DMF along with higher energy charge transfer bands. While complex 1 is a poor binder to DNA, the ternary complexes show good DNA binding propensity. The photo-nuclease activity of 1-3 is studied using UV and visible wavelengths. The DNA cleavage activity at 365 nm follows the order: 3 > 2 > 1. The cleavage reaction involves the formation of singlet oxygen as the reactive species in a type-II process.

Original languageEnglish (US)
Pages (from-to)123-132
Number of pages10
JournalJournal of Chemical Sciences
Volume117
Issue number2
DOIs
StatePublished - Jan 1 2005
Externally publishedYes

Fingerprint

Sulfur
Copper
DNA
Bond length
Quinoxalines
Singlet Oxygen
Tromethamine
Imines
Schiff Bases
Electrolytes
Binders
Charge transfer
X ray diffraction
Wavelength
Atoms
Geometry
2-ethylpyridine
perchlorate

Keywords

  • Copper (II) complexes
  • Crystal structure
  • DNA photo-cleavage
  • Phenanthroline bases
  • Schiff base

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Effect of copper-sulphur bond on the DNA photo-cleavage activity of 2-(methylthio)ethylpyridine-2-carbaldimine copper(II) complexes. / Gupta, Tarkeshwar; Patra, Ashis K.; Dhar, Shanta; Nethaji, Munirathinam; Chakravarty, Akhil R.

In: Journal of Chemical Sciences, Vol. 117, No. 2, 01.01.2005, p. 123-132.

Research output: Contribution to journalArticle

Gupta, Tarkeshwar ; Patra, Ashis K. ; Dhar, Shanta ; Nethaji, Munirathinam ; Chakravarty, Akhil R. / Effect of copper-sulphur bond on the DNA photo-cleavage activity of 2-(methylthio)ethylpyridine-2-carbaldimine copper(II) complexes. In: Journal of Chemical Sciences. 2005 ; Vol. 117, No. 2. pp. 123-132.
@article{8a6ddaad75644c8196f6f907dd16ff89,
title = "Effect of copper-sulphur bond on the DNA photo-cleavage activity of 2-(methylthio)ethylpyridine-2-carbaldimine copper(II) complexes",
abstract = "The binding and photo-induced DNA cleavage activity of a binary complex [CuL2](ClO4)2 (1) and the in situ generated ternary complexes [CuLB](ClO4)2 from 1 (B: 1,10-phenanthroline, phen, 2; dipyrido[3,2-d: 2′,3′-f]quinoxaline, dpq, 3) are studied, where L is a N2S-donor tridentate Schiff base 2-(methylthio)ethylpyridine-2-carbaldimine. Complex 1, structurally characterized by X-ray diffraction study, has six-coordinate meridional geometry snowing CuN4S2 coordination. The Cu-N bond lengths are in the range of 1·968(3) to 2·158(4) {\AA}. The Cu-S bond lengths of 2-599(2) and 2-705(2) {\AA} are significantly long indicating weak covalent interaction between copper and sulphur atoms. The thiomethyl groups are cis to each other giving S-Cu-S angle of 75-82(5)°. The Cu-N(pyridyl) bond distances are longer than the Cu-N(imine) bonds. The complexes are redox active and display a quasi-reversible cyclic voltammetric response assignable to the Cu(II)/Cu(I) couple near 0-0 V vs SCE in DMF-Tris buffer (1:4 ν/ν) using 0·1 M KCl as supporting electrolyte. Electronic spectra of the complexes show a d-d band in the range 630 to 700 nm in DMF along with higher energy charge transfer bands. While complex 1 is a poor binder to DNA, the ternary complexes show good DNA binding propensity. The photo-nuclease activity of 1-3 is studied using UV and visible wavelengths. The DNA cleavage activity at 365 nm follows the order: 3 > 2 > 1. The cleavage reaction involves the formation of singlet oxygen as the reactive species in a type-II process.",
keywords = "Copper (II) complexes, Crystal structure, DNA photo-cleavage, Phenanthroline bases, Schiff base",
author = "Tarkeshwar Gupta and Patra, {Ashis K.} and Shanta Dhar and Munirathinam Nethaji and Chakravarty, {Akhil R.}",
year = "2005",
month = "1",
day = "1",
doi = "10.1007/BF03356106",
language = "English (US)",
volume = "117",
pages = "123--132",
journal = "Proceedings of the Indian Academy of Sciences - Section A",
issn = "0370-0089",
publisher = "Indian Academy of Sciences",
number = "2",

}

TY - JOUR

T1 - Effect of copper-sulphur bond on the DNA photo-cleavage activity of 2-(methylthio)ethylpyridine-2-carbaldimine copper(II) complexes

AU - Gupta, Tarkeshwar

AU - Patra, Ashis K.

AU - Dhar, Shanta

AU - Nethaji, Munirathinam

AU - Chakravarty, Akhil R.

PY - 2005/1/1

Y1 - 2005/1/1

N2 - The binding and photo-induced DNA cleavage activity of a binary complex [CuL2](ClO4)2 (1) and the in situ generated ternary complexes [CuLB](ClO4)2 from 1 (B: 1,10-phenanthroline, phen, 2; dipyrido[3,2-d: 2′,3′-f]quinoxaline, dpq, 3) are studied, where L is a N2S-donor tridentate Schiff base 2-(methylthio)ethylpyridine-2-carbaldimine. Complex 1, structurally characterized by X-ray diffraction study, has six-coordinate meridional geometry snowing CuN4S2 coordination. The Cu-N bond lengths are in the range of 1·968(3) to 2·158(4) Å. The Cu-S bond lengths of 2-599(2) and 2-705(2) Å are significantly long indicating weak covalent interaction between copper and sulphur atoms. The thiomethyl groups are cis to each other giving S-Cu-S angle of 75-82(5)°. The Cu-N(pyridyl) bond distances are longer than the Cu-N(imine) bonds. The complexes are redox active and display a quasi-reversible cyclic voltammetric response assignable to the Cu(II)/Cu(I) couple near 0-0 V vs SCE in DMF-Tris buffer (1:4 ν/ν) using 0·1 M KCl as supporting electrolyte. Electronic spectra of the complexes show a d-d band in the range 630 to 700 nm in DMF along with higher energy charge transfer bands. While complex 1 is a poor binder to DNA, the ternary complexes show good DNA binding propensity. The photo-nuclease activity of 1-3 is studied using UV and visible wavelengths. The DNA cleavage activity at 365 nm follows the order: 3 > 2 > 1. The cleavage reaction involves the formation of singlet oxygen as the reactive species in a type-II process.

AB - The binding and photo-induced DNA cleavage activity of a binary complex [CuL2](ClO4)2 (1) and the in situ generated ternary complexes [CuLB](ClO4)2 from 1 (B: 1,10-phenanthroline, phen, 2; dipyrido[3,2-d: 2′,3′-f]quinoxaline, dpq, 3) are studied, where L is a N2S-donor tridentate Schiff base 2-(methylthio)ethylpyridine-2-carbaldimine. Complex 1, structurally characterized by X-ray diffraction study, has six-coordinate meridional geometry snowing CuN4S2 coordination. The Cu-N bond lengths are in the range of 1·968(3) to 2·158(4) Å. The Cu-S bond lengths of 2-599(2) and 2-705(2) Å are significantly long indicating weak covalent interaction between copper and sulphur atoms. The thiomethyl groups are cis to each other giving S-Cu-S angle of 75-82(5)°. The Cu-N(pyridyl) bond distances are longer than the Cu-N(imine) bonds. The complexes are redox active and display a quasi-reversible cyclic voltammetric response assignable to the Cu(II)/Cu(I) couple near 0-0 V vs SCE in DMF-Tris buffer (1:4 ν/ν) using 0·1 M KCl as supporting electrolyte. Electronic spectra of the complexes show a d-d band in the range 630 to 700 nm in DMF along with higher energy charge transfer bands. While complex 1 is a poor binder to DNA, the ternary complexes show good DNA binding propensity. The photo-nuclease activity of 1-3 is studied using UV and visible wavelengths. The DNA cleavage activity at 365 nm follows the order: 3 > 2 > 1. The cleavage reaction involves the formation of singlet oxygen as the reactive species in a type-II process.

KW - Copper (II) complexes

KW - Crystal structure

KW - DNA photo-cleavage

KW - Phenanthroline bases

KW - Schiff base

UR - http://www.scopus.com/inward/record.url?scp=17044388161&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=17044388161&partnerID=8YFLogxK

U2 - 10.1007/BF03356106

DO - 10.1007/BF03356106

M3 - Article

VL - 117

SP - 123

EP - 132

JO - Proceedings of the Indian Academy of Sciences - Section A

JF - Proceedings of the Indian Academy of Sciences - Section A

SN - 0370-0089

IS - 2

ER -