Hypoxanthine, xanthine and theobromine complexes with palladium(II) and platinum(IV) chlorides

Mikulski, Chester M.; Grossman, Scott J.; Lee, Chung Ja; Karayannis, Nicholas M.

doi:10.1007/bf01023123

Cited by 13 publications

(3 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…tbH is an important alkaloid. It has been investigated by scientists for many years because of its commercial and scientific importance (Cook and Regnier 1967, Mikulski et al 2007, Ford et al 1998. It is also known with biological and pharmacological activities in living organisms (Oettle andReibnegger 1999, Tewari et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Studies on Theobromine and Theobromine-Water Complexes

Bilkan¹

2018

AKU-J. Sci. Eng.

View full text Add to dashboard Cite

In this study, the solvent effects on structural, spectroscopic, electronic and thermochemical properties of Theobromine (tbH) were theoretically investigated. The dichloromethane (DCM), dimethylsulfoxide (DMSO) and water (H2O) solvents have been chosen for investigations. Optimized molecular structures of tbH were obtained by using the DFT/B3LYP method with 6-311++G(d,p) basis set in vacuum and in solvent media. Calculated geometric structure parameters were compared with experimental data. In the experimental section, the mid-IR spectrum of tbH was recorded using ATR equipment and compared with calculated vibrational frequencies. tbH-H2O complexes were studied for various binding ratios. The total energies and hydrogen bond lengths of these complexes were discussed in detail. It is seen as the result of this study that N⋯H-O and O⋯H-O non-covalent bonded structures are more stable for all binding versions and hydrogen bond lengths for all tbH-H2O complexes range from 1.8-2.5 Å.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Studies on Theobromine and Theobromine-Water Complexes

Bilkan¹

2018

AKU-J. Sci. Eng.

View full text Add to dashboard Cite

show abstract

“…Thus, an interaction with a rich metal center is also predicted. In fact, N(9) complexes of caffeine are well known [2,60,[62][63][64][65][66], and there are examples reported with theobromine [3,[67][68][69]. The latter one also displays an acidic nature (LUMO) onto N(1), substituted by a proton.…”

Section: Resultsmentioning

confidence: 94%

“…The latter one also displays an acidic nature (LUMO) onto N(1), substituted by a proton. Some N(1) bounded species of theobromine have previously been reported [68].…”

Section: Resultsmentioning

confidence: 97%

Studies on the coordination chemistry of methylated xanthines and their imidazolium salts. Part 1: benzyl derivatives

Landaeta

Rodríguez-Lugo

Rodríguez-Arias

et al. 2009

Transition Met Chem

View full text Add to dashboard Cite

New imidazolium salts derived from the natural methylated xanthines theophylline, theobromine and caffeine, namely 1,3-dimethyl-9-benzylxanthinium bromide (tphBzBr, 1a), 3,7-dimethyl-9-benzylxanthinium bromide (tbrBzBr, 2a) and 1,3,7-trimethyl-9-benzylxanthinium bromide (caffBzBr, 3a), are reported. Also, the disubstituted analog of 1a, 1,3-dimethyl-7,9-dibenzylxanthinium bromide (tphBz 2 Br, 1a 0 ) was identified and characterized by NMR. The coordination chemistry of ligands 1a-3a toward palladium, and some theoretical aspects of the unmodified theophylline, theobromine and caffeine are studied. Our results prove that the theophylline derivative has the thermodynamic tendency to form N-bonded species, even when an equilibrium between the Pd-NHC and the ''theophyllinate'' was observed spectroscopically, due to the anisotropy of the NHC ligand. To confirm the Ncoordination, the solid state structure of the new ''theophyllinate'' species PdBr 2 (tphBz-H) 2 (4), derived from 1a, was determined by X-ray diffraction. The analog with theobromine, ligand 2a, coordinates to palladium via N1, in an analogous manner to 1a, and a mixture of the cis/trans isomers of its palladium complex is obtained. On the other hand, since there is no possibility of N-coordination in 3a, this caffeine derivative forms a Pd-NHC compound after deprotonation with a strong base. Both the theoretical results and the experimental evidence are in accordance, in terms of the predicted coordination sites or possibility of modification of the selected methylated xanthines to obtain new ligands.

show abstract

Nicke(II) halide complexes with hypoxanthine and xanthine

Mikulski

Gaul

Bayne

et al. 1989

Transition Met Chem

View full text Add to dashboard Cite

Hypoxanthine, xanthine and theobromine complexes with palladium(II) and platinum(IV) chlorides

Cited by 13 publications

References 47 publications

Experimental and Theoretical Studies on Theobromine and Theobromine-Water Complexes

Experimental and Theoretical Studies on Theobromine and Theobromine-Water Complexes

Studies on the coordination chemistry of methylated xanthines and their imidazolium salts. Part 1: benzyl derivatives

Nicke(II) halide complexes with hypoxanthine and xanthine

Contact Info

Product

Resources

About