abstract
Two new coordination complexes were synthesized, which are formulated as [Cu-2(cis-1,4-chdc)(4,4' -Me(2)bpy)(4)] & sdot; 2(ClO4-) & sdot; H2O (1) and [Cu-2(cis-1,4-chdc)(5,5' -Me(2)bpy)(4)] & sdot; 2(ClO4-) & sdot; H2O (2), using cis-1,4-cyclohexanedicarboxylic acid (cis-1,4-H(2)chdc), 4,4 '-dimethyl-2,2 '-bipyridine (4,4' -Me(2)bpy), 5,5' -dimethyl-2,2' -bipyridine (5,5' -Me2bpy). Interestingly, cis-1,4-chdc adopts chair form in 1 and boat conformation in 2. This conformational change impacts the DNA binding capacities of the complexes as revealed by spectrophotometry, circular dichroism (CD) spectroscopy and docking studies. The complex 1 having the chair conformation shows higher affinity towards the DNA base pairs due to anti-alignment of the planar aromatic pyridyl rings of 4,4' -Me(2)bpy, which strongly intercalates with the adenosine base pairs of DNA by formation of three pi-pi stacking and two extra pi-positive stacking interactions between adenosine bases and positively charged nitrogen. Conversely, 5,5 '-Me2bpy with planar aromatic pyridyl rings of complex 2 shows bis-intercalation with weak affinities toward base pairs by formation of two pi-pi stacking and one pi-positive stacking interactions.
keywords
COORDINATION-COMPLEXES; ANTICANCER; OXIDATION; CHEMISTRY; CHIRALITY
subject category
Chemistry
authors
Rahaman, SK; Mohammad, M; Brandao, P; Siddiqui, MR; Wabaidur, SM; Islam, MM; Alam, SM; Mir, MH
our authors
Paula Cristina Ferreira da Silva Brandão
Assistant ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work was supported by SERB India (Grant No. CRG/2022/001842, dated 19/12/2022). P. B. gratefully acknowledges the financial support of this work by the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). Authors are grateful to the Researchers Supporting Project Number (RSP2023R326), King Saud University, Riyadh, Saudi Arabia.