Synthesis, structure, proton-nuclear magnetic resonance, and Fourier transform infrared spectroscopy of several transition and nontransition metal–adenosine-5-triphosphate complexes

1986 ◽  
Vol 64 (5) ◽  
pp. 960-966 ◽  
Author(s):  
H. A. Tajmir-Riahi ◽  
M. J. Bertrand ◽  
T. Theophanides
Keyword(s):  
Metal Binding ◽  
Disodium Salt ◽  
Proton Nuclear Magnetic Resonance ◽  
Metal Phosphate ◽  
Nontransition Metal ◽  
Infrared Band ◽  
Spectral Changes ◽  
Anti Conformation ◽  
Marker Band ◽  
Cis And Trans

Several complexes of adenosine-5-triphosphate disodium salt (Na2H2ATP) with the metal ions, Na+, Mg2+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+, and cis- and trans-Pt(NH3)2Cl2 and K2PtCl4 at pH = 3.5 and 7.2 have been isolated, identified, and studied. Marked spectral similarities have been observed for the structurally known metal–phosphate bonded compounds, [Cu(H2ATP)(phen)]2•7H2O and [Zn(H2ATP)(bipy)]2•4H2O and all the metal–ATP complexes studied here, except the Pt–ATP complexes. The metal binding is through the α, β, and γ phosphate oxygen atoms when the N1-position of adenine is protonated. Spectral changes have also been observed for the Pt–ATP complexes in which there is a Pt–N7 and –N1 coordination. The sugar pucker in the Na2H2ATP•3H2O crystal dimers is C3′-endo–anti (in one) and C2′-endo–anti (in the other) with a characteristic infrared band at 818 cm−1. In the corresponding Cu2+ and Zn2+ complexes the sugar has C3′-endo–anti conformation with the marker band at about 814 cm−1. The C2′-endo–anti conformation is observed for all the metal–ATP complexes prepared here with a marker band at 825–822 cm−1.

An FT-ir study of cis study of trans-dichlorodiammineplatinum(II) bound to inosine-5′-monophosphate

1984 ◽  
Vol 62 (8) ◽  
pp. 1429-1440 ◽  
Author(s):  
H. A. Tajmir-Riahi ◽  
T. Theophanides
Keyword(s):  
Trans Isomer ◽  
Platinum Complexes ◽  
Disodium Salt ◽  
Spectral Changes ◽  
Ir Studies ◽  
Stretching Vibration ◽  
Ft Ir ◽  
Purine Ring ◽  
Ir Study ◽  
Cis And Trans

Inosine-5′-monophosphate disodium salt (5′-IMPNa2) reacts with cis-dichlorodiammineplatinum(II) (cis-DDP) and its trans-isomer (trans-DDP) to give complexes of the type cis- and trans-Pt(NH3)2(IMPNa2)nCl2•xH2O, n = 1 or 2 and Pt(IMPNa2)nCl2•xH2O, where n = 1, 2, or 3 and x = 0–6. In the 1:2 platinum complexes the nucleotide binds only to the N7-atom of the purine ring system, while in the 1:1 metal complexes there is indication for Pt–carbonyl interaction (bridging or chelation) in addition to the N7-bonding at neutral pH values with cis-DDP.Solution FT-ir studies (H2O and D2O) showed that the 1:1 species formed with cis-DDP at neutral pH's behaved differently from those with trans-DDP. The carbonyl stretching vibration of the free base at 1685 cm−1 (H2O) and 1670 cm−1 (D2O) exhibited marked spectral changes in intensity, shifting, and shape upon complexation, whereas the reaction with the trans-isomer produced only slight perturbations in the above region.

Characterisation of a Binary Transition Metal Complex of a Purine 3′ -Nucleotide, {[Cu3(3′ -GMP)2(3′ -GMPH)2(H2O)5]·7H2O}n. [1]. Phosphate-only Binding of Copper(II)

1983 ◽  
Vol 38 (1) ◽  
pp. 16-19 ◽  
Author(s):  
W. S. Sheldrick
Keyword(s):  
Aqueous Solution ◽  
Metal Complex ◽  
Copper Atom ◽  
Metal Binding ◽  
Transition Metal Complex ◽  
The Other ◽  
Monoclinic Space Group ◽  
Water Oxygen ◽  
Anti Conformation ◽  
Guanine Base

Abstract {[Cu3(3′-GMP)2(3′-GMPH)2(H2O)5]·7H2O}n (1) was isolated from an aqueous solution of Cu(NO3)2 and guanosine 3′-monophosphate at a pH of 4.4. 1 is monoclinic space group C 2 with a = 29.140(7), b = 6.865(5), c = 16.980(7) Å, β = 90.31(3)°, Z = 2, Dc = 1.81 g·cm-3. The structure was refined to R - 0.065 with i?w = 0.060 for 2642 independent reflections. It is disordered about a crystallographic diad axis with one of the copper atoms Cu(2) sited on this axis. This and the other independent copper atom Cu(l) both display square pyramidal geometries. Cu(l) binds N(7) of a guanine base, two phosphate O atoms of nucleotide molecules not symmetry-related to one another and two water oxygens. The guanine base involved in this coordination adopts a syn-conformation relative to the ribose ring with χCN= -118.5°. Cu(2) is coordinated by four phosphate O atoms of different nucleotide molecules and one water oxygen. The second guanine base, which is not involved in metal binding, displays the anti-conformation relative to the ribose ring.

A Fourier transform infrared study of the electrophilic attack at the N7-site of guanosine-5′-monophosphate

1984 ◽  
Vol 62 (2) ◽  
pp. 266-272 ◽  
Author(s):  
H. A. Tajmir-Riahi ◽  
T. Theophanides
Keyword(s):  
Fourier Transform ◽  
Infrared Spectra ◽  
Fourier Transform Infrared ◽  
Divalent Metal ◽  
Ring System ◽  
Disodium Salt ◽  
Divalent Metal Ions ◽  
Electrophilic Attack ◽  
Infrared Study ◽  
Spectral Changes

Fourier transform infrared spectra of several N7-bound cations of guanosine-5′monophosphate disodium salt (5′-GMPNa2), such as N7-H+GMP, N7-MeGMP, and N7-MGMP, where Me = CH3+ and M = divalent metal ions, Cd, Mn, Co, Ni, Cu, Pt, and Mg, have been recorded and a correlation between the spectral changes and the nature of the electrophile (H+, CH3+, and M2+) bound has been established. Spectroscopic evidence shows that methylation of the N7-position of 5′-GMPNa2 causes larger perturbation on the guanine ring system than protonation or metalation, in the order Me+ > H+ > M2+. The effect of an N7-electrophilic attack on the vibrational frequencies of the purine, the sugar, and the phosphate group is discussed.

In situ Fourier transform infrared spectroelectrochemical studies of the oxidation of some octaethylporphyrin complexes

1993 ◽  
Vol 71 (12) ◽  
pp. 1975-1982 ◽  
Author(s):  
A. Scott Hinman ◽  
Temitayo Olorunyolemi
Keyword(s):  
Cation Radical ◽  
Porphyrin Ring ◽  
In Situ Ftir ◽  
Metal Centre ◽  
Initial Oxidation ◽  
Porphyrin Ligand ◽  
Spectral Changes ◽  
Marker Band ◽  
Absorbance Band

The oxidations of OEPNi(II), OEPCu(II), OEPFe(III)Cl, OEPMn(III)ClO4, OEPAg(II), OEPCo(II), and OEPZn(II) (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrin dianion) have been studied by in situ FTIR reflectance spectroelectrochemistry in dibromomethane. One-electron oxidation of the porphyrin ring to produce a π-cation radical results in the appearance of a strong new absorbance band near 1550 cm−1. Other features typical of π-cation radical formation are a strong absorbance increase near 1470 cm−1, and absorbance decreases near 1270 and 1018 cm−1. Oxidation of the metal centre, as observed for OEPCo(II) in the presence of CH3CN, and for OEPAg(II), results in considerably less perturbation of the vibrational spectra of the complexes. For OEPCo(II) in dry dibromomethane, initial oxidation at the porphyrin ligand is followed by a second oxidation at the metal centre. This order is reversed when acetonitrile is added to solution. Production of porphyrin π-dications was observed for OEPCu(II) and OEPNi(II). This results in a shift of the 1550 cm−1 π-cation radical marker band to higher energy, and a strong absorbance increase near 1380 cm−1. Unusual spectral changes observed on one-electron oxidation of OEPZn(II) are suggested to result from the formation of a dimer.

The effect of metal binding on the characteristic infrared band intensities of ligands of biological interest

2012 ◽  
Vol 1009 ◽  
pp. 83-88 ◽  
Author(s):  
Todor Dudev ◽  
Carmay Lim
Keyword(s):  
Metal Binding ◽  
Infrared Band ◽  
Biological Interest

Hexafluoroisopropylidene based sulfonated new copolytriazoles: investigation of proton exchange membrane properties

e-Polymers ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Asheesh Singh ◽  
Anaparthi Ganesh Kumar ◽  
Soumendu Bisoi ◽  
Sayantani Saha ◽  
Susanta Banerjee
Keyword(s):  
Proton Exchange Membrane ◽  
Click Reaction ◽  
Repeat Unit ◽  
Disodium Salt ◽  
Proton Exchange ◽  
Proton Nuclear Magnetic Resonance ◽  
Membrane Properties ◽  
Disulfonic Acid ◽  
Unit Structure ◽  
Exchange Membrane

AbstractA series of novel sulfonated polytriazole copolymers (PTFOSH-XX) was successfully prepared by the click reaction of 4,4′-(perfluoropropane-2,2-diyl)bis((prop-2-ynyloxy)benzene (TF), 4,4′-diazido-2,2′-stilbene disulfonic acid disodium salt (SAZ) and 4,4′-diazidodiphenyl ether (OAZ). The copolymers were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (NMR) spectroscopy. The copolymers showed high mechanical, thermal and oxidative stability and low swelling. The phase separated morphology of the membranes was confirmed from transmission electron microscopy (TEM). The membranes showed proton conductivity as high as 110 and 122 mS cm−1 at 80 and 90°C, respectively depending on the polymer repeat unit structure.

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