Redetermination of bis(<scp>L</scp>-asparaginato)copper(II)

Vencato, Ivo; Lariucci, Carlito; Ferreira, K.D.; Santana, Ricardo Costa de; Carvalho, J. F.

doi:10.1107/s1600536804022202

Cited by 7 publications

(7 citation statements)

References 5 publications

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“…The solid‐state copper(II)‐ l ‐Asn complexes were characterized by the IR spectra [Cu( l ‐Asn) 2 , Cu( l ‐His)( l ‐Asn)], a Raman spectrum of Cu( l ‐Asn) 2 , the electron paramagnetic resonance (EPR) spectra of Cu( l ‐Asn) 2 , and by the X‐ray single crystal structural analysis . Cu( l ‐Asn) 2 crystallized as an anhydrous trans compound . The X‐ray crystal and molecular structures of an anhydrous Cu( l ‐His)( l ‐Asn) complex and an aqua trihydrate [Cu( l ‐His)( l ‐Asn)(H 2 O)⋅3H 2 O] modification were determined …”

Section: Introductionsupporting

confidence: 87%

“…In addition to the approach described above, the experimental X‐ray crystal structures of Cu( l ‐Asn) 2 , Cu( l ‐His)( l ‐Asn), and [Cu( l ‐His)( l ‐Asn)(H 2 O)⋅3H 2 O] were used as the starting coordinates for geometry optimizations in the gas phase and in aqueous surroundings using PCM. The superposition of the resulting calculated and experimental structures is illustrated in Figures –10.…”

Section: Resultsmentioning

confidence: 99%

“… Superposition of the Cu( l ‐Asn) 2 structures with respect to each chelate ring. The experimental X‐ray molecular structure is denoted light blue, and the B3LYP estimated gas‐phase and PCM aqueous equilibrium structures are orange and brown, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Cu( l ‐Asn) 2 . The coordination mode in the X‐ray crystal structure is trans ‐NONO . The compound has the side chains in an axial and an equatorial position with respect to the chelate rings, and N am −C α −C β −C ad ≈−60°.…”

Section: Resultsmentioning

confidence: 99%

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Conformational Analyses of Physiological Binary and Ternary Copper(II) Complexes with l‐Asparagine and l‐Histidine; Study of Tridentate Binding of Copper(II) in Aqueous Solution

et al. 2019

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This study explores the structural properties and energy landscapes of the physiologically important bis( l ‐asparaginato)copper(II) [Cu( l ‐Asn) 2 ] and ( l ‐histidinato)( l ‐asparaginato)copper(II) [Cu( l ‐His)( l ‐Asn)]. The conformational analyses in the gas phase and implicitly modeled water medium, and magnetic parameters of electron paramagnetic resonance spectra were attained using density functional theory calculations. The apical Cu II coordination and hydrogen bonding were analyzed. Predicted lower‐energy structures enabled the confirmation and, for apical bonding, also the refinement of structural proposals from literature. Available experimental results were indecisive regarding the amido‐group binding in the Cu II equatorial plane in solutions, but the examination of the relative stability of Cu( l ‐Asn) 2 conformers in 30 binding modes confirms the glycine‐like mode as the most stable one. Previously reported experimental results for Cu( l ‐His)( l ‐Asn) were interpreted for l ‐His to have a tridentate histamine‐like mode. However, the aqueous conformers with l ‐His in the glycinato mode are also predicted to have low energies, which does not contradict the tridentate l ‐His binding. The predicted magnetic parameters of conformers with an apical oxygen atom (intramolecular or from a water molecule) can reproduce the experimental data. An extent of conformational flexibility and abundance of l ‐His‐containing ternary copper(II) amino acid complexes under physiological conditions may be related.

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Section: Introductionsupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Conformational Analyses of Physiological Binary and Ternary Copper(II) Complexes with l‐Asparagine and l‐Histidine; Study of Tridentate Binding of Copper(II) in Aqueous Solution

et al. 2019

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“…The respective copper salt (Stephens et al 1975; redetermined by Venkato et al 2004) has a chain structure similar to its threoninate analog, where isolated [4 + 1] copper pyramids are connected to a chain. As in the threoninate, there are two different asparaginate anions, one bridging mode between two pyramids, the other one coordinating only one cation (Fig.…”

Section: Tris(l-cysteinato-s)-bismuth Monohydrate Comprises [3]-coordmentioning

confidence: 97%

Compounds of Amino Acids as Anions

Fleck

Petrosyan

2014

Salts of Amino Acids

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This chapter deals with salts formed from metal cations and amino acid anions. All amino acids can act as monovalent anion; the acidic members glutamic acid and aspartic acid as well as cysteine and tyrosine can form both monovalent and divalent anions. Due to the large number of available cations, a multitude of combinations is possible and in fact found (for the standard twenty amino acids, over 150 crystal structures are published, and many more species have been characterized by other methods). Different hydration states (as reported for the pristine amino acid crystals) occur as well, and the existence of polymorphs is also documented for some cases. The formation of metal-amino acid complexes has been studied in several works (both for a given amino acid and a given cation), and the flexibility of amino acid molecules as ligands allows coordination of cations with different chemical properties (such as charge or ionic radius). Several coordination modes are found for amino acids -the molecules can act as monodentate, bidentate, tridentate, and bridging ligands. The connectivity of the coordination polyhedra of the metal cations is considered -isolated units are frequent, but chains and layers occur as well. Moreover, these units can connect via amino acid molecules to form higher-dimensional structures. Hydrogen bonds (also involving water molecules, both in coordination or in the interstices as crystal water) further stabilize the units, forming relatively stable phases. The frequency of salts varies among the different amino acids, and most examples are reported for glycinate salts, whereas crystals of cations and basic and weakly soluble amino acids are difficult to obtain (e.g., arginate and lysinate salts have not been reported in crystalline state). Finally, the aspect of symmetry is considered (the chirality of most amino acids playing a crucial role), and, consequently, the properties of these salts have impact on applications in the fields of physics, biology, and medicine.

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