Efficient Artificial Nucleases for Mediating DNA Cleavage Based on Tuning the Steric Effect in the Pyridyl Derivatives of Tripod Tetraamine‐Cobalt(II) Complexes

Abstract

Four cobalt(II) complexes [Co(L 1 )Cl]PF 6 /ClO 4 (C1-PF 6 / C1-ClO 4 ), [Co(L 2 )Cl]PF 6 (C2-PF 6 ), [Co(L 3 )Cl]PF 6 /ClO 4 ·H 2 O·CH 3 OH (C3-PF 6 /C3-ClO 4 ·H 2 O·CH 3 OH) and [Co(L 4 [bis(3,5-dimethyl-4methoxy-2-pyridylmethyl)-(2-pyridylmethyl)]amine and {[bis-(3,4-dimethoxy-2-pyridyl)methyl]-(2-pyridylmethyl)}amine, respectively, were synthesized and structurally characterized. Single-crystal X-ray crystallography confirmed the trigonal bipyramidal geometries of the complexes. In aqueous acetonitrile solution, the green complexes dissolve with the formation of a yellow solution with biphasic kinetic behavior. In 60 % H 2 O/ [a]

Steric Effects of Alkyl Substituents at N-Donor Bidentate Amines Direct the Nuclearity, Bonding and Bridging Modes in Isothiocyanato-Copper(II) Coordination Compounds

“…The coordination compounds were also characterized by IR, UV-Vis, and by single crystal X-ray crystallography. Probably, it is interesting to mention that although the µ-1,3and µ-1,1-bonding modes are common in bridging-azido-metal(II) coordination compounds [8,9,11,12,[14][15][16], the corresponding µ-1,1-bonding in the bridging-isothiocyanato compounds is rare [32][33][34] and in most cases alternating µ-1,3-bonding chains are observed [1][2][3][4][5][6][7]17,[21][22][23][24][25][26][27][28][29][30][31].…”

“…However, the formation of these compounds depends largely on a number of factors which include the electronic nature and oxidation state of the metal ion, the nature of the coordinated ancillary co-ligand(s), its skeletal structure, and the steric hindrance imposed by the blocking co-ligand(s) surrounding the central metal ion [11,12]. Steric effects caused by the coordinating blocking ligands in coordination compounds have been reported to produce a dramatic effect on the structural and magnetic behavior of pseudohalide coordination compounds [1][2][3][4][5][6][7][8][9][10][11][13][14][15][16] but also in the biological catalytic reactions of the P-O bond cleavage in DNA and phosphodiester hydrolysis [17][18][19][20].…”

“…Crystals 2019, 9, x FOR PEER REVIEW 2 of 16 dramatic effect on the structural and magnetic behavior of pseudohalide coordination compounds [1][2][3][4][5][6][7][8][9][10][11][13][14][15][16] but also in the biological catalytic reactions of the P-O bond cleavage in DNA and phosphodiester hydrolysis [17][18][19][20]. Isothiocyanato coordination compounds are considered as among the most studied systems in coordination chemistry due to the diverse bonding properties of the NCS − ion as an ambidentate and bridging ligand that can bind two or more metal ions simultaneously as well as its ability to propagate magnetic interaction between bridged paramagnetic metal ions.…”

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N 4-donor ligand

“…In the last two decades, our group and others have exploited mononuclear first-row transition-metal complexes containing two labile cis ligands as biomimetic or bio-inspired homogeneous catalysts for a great variety of reactions, such as the oxidation of catechol and cyclohexane (Ferre et al, 2017), the hydrolysis of proteins (Oliveira et al, 2009), phosphodiesters (Scarpellini et al, 2003;Kettenmann et al, 2018) and polysaccharides (Concia et al, 2017), and, more recently, water splitting (Luo et al, 2016). They have also been studied as prodrugs and carrier prototypes for the selective delivery of bioactive substances (Pires et al, 2016;de Souza et al, 2016).…”

Steric Effects of Alkyl Substituents at <em>N</em>-Donor Bidentate Amines Direct the Nuclearity, Bonding and Bridging Modes in Thiocyanato-Copper(II) Complexes

“…However, the formation of these compounds depends largely on a number of factors which include which include electronic nature and oxidation state of metal ion, the nature of the coordinated ancillary co-ligand(s), its skeletal structure, and the steric hindrance imposed by the blocking coligand(s) surrounding the central metal ion [11,12]. Steric effects caused by the coordinating blocking ligands in metal complexes have been reported to produce a dramatic effect on the structural and magnetic behavior of pseudohalide complexes [1][2][3][4][5][6][7][8][9][10][11][13][14][15][16] but also in the biological catalytic reactions of the P-O bond in DNA and phosphodiester hydrolysis [17][18][19][20].…”