1
|
Talib SH, Hussain S, Muhammad S, Baskaran S, Iqbal J, Ayub K. Exploring the potential of novel transition metal complexes derived from ONO donor type ligand: a quantum chemical study. J Mol Model 2019; 25:284. [PMID: 31468196 DOI: 10.1007/s00894-019-4157-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 08/14/2019] [Indexed: 10/26/2022]
Abstract
In the present quantum chemical investigation, we predict several novel transition metal complexes which are designed using tridentate ONO donor type Schiff base ligand (2-((E)-((Z)-4-hydroxypent-3-en-2-ylidene) amino) phenol). The stable molecular geometries of newly designed metal complexes are obtained using density functional theory (DFT) methods. Several properties including geometrical parameters, energies of frontier molecular orbitals (FMOs), and interaction energies are calculated for optimized metal complexes. The more negative interaction energies illustrate more susceptibilities of the reaction of metal cations with ligand. The charge transfers from ligand to metals are observed in the d7 and d8 metal complexes while it is seen as backdonation of charge from metal to ligand in the d10 complexes. The quantum chemical characterizations are performed for calculating UV-visible spectra and IR frequencies for all the designed metal complexes. All designed metal complexes show multiple absorption peaks in UV region ranging from 184 to 376 nm, which are related to metal to ligand and ligand to metal charge transfer processes. The IR frequency analysis shows that the -C=N- stretching frequency of ligand in the region of 1650-1580 cm-1 is decreased by between 50 and 100 cm-1, which may assign the coordination of ligand with metal via nitrogen. Moreover, the investigations of nonlinear optical (NLO) polarizabilities among selected complexes show that these complexes may possess good potential for NLO applications. The most interesting results are found about the third-order NLO polarizabilities (γ||) where the γ|| amplitudes are found to be 60.01 × 10-36, 56.48 × 10-36, 90.04 × 10-36, and 64.57 × 10-36 esu for complexes 1, 2, 9, and 10, respectively. Thus, we believe that the present investigation may bring the newly designed metal complexes in the limelight of scientific interest for their practical realization in optical and nonlinear optical applications. Graphical abstract Several novel transition metal complexes are designed using tridentate ONO donor type Schiff base ligand as efficient NLO materials.
Collapse
Affiliation(s)
- Shamraiz Hussain Talib
- Theoretical and Computational Laboratory, Department of Chemistry, Tsinghua University, Beijing, 100084, People's Republic of China.,Department of Chemistry, Mohi-ud-Din Islamic University, Nerian Sharif, Azad Jammu & Kashmir, Pakistan
| | - Sajjad Hussain
- Department of Chemistry, Mohi-ud-Din Islamic University, Nerian Sharif, Azad Jammu & Kashmir, Pakistan.,Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, 453007, China
| | - Shabbir Muhammad
- Department of Physics, College of Science, King Khalid University, P.O. Box 9004, Abha, 61413, Saudi Arabia.
| | - Sambath Baskaran
- Theoretical and Computational Laboratory, Department of Chemistry, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Javed Iqbal
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad, 38000, Pakistan
| | - Khurshid Ayub
- Department of Chemistry, COMSATS University, Abbottabad Campus, Abbottabad, KPK, 22060, Pakistan
| |
Collapse
|
2
|
Milovanović MR, Andrić JM, Medaković VB, Djukic JP, Zarić SD. Investigation of interactions in Lewis pairs between phosphines and boranes by analyzing crystal structures from the Cambridge Structural Database. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2018; 74:255-263. [PMID: 29927388 DOI: 10.1107/s2052520618003736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/04/2018] [Indexed: 06/08/2023]
Abstract
The interactions between phosphines and boranes in crystal structures have been investigated by analyzing data from the Cambridge Structural Database (CSD). The interactions between phosphines and boranes were classified into three types; two types depend on groups on the boron atom, whereas the third one involves frustrated Lewis pairs (FLPs). The data enabled geometric parameters in structures to be compared with phosphine-borane FLPs with classical Lewis pairs. Most of the crystal structures (78.1%) contain BH3 as the borane group. In these systems, the boron-phosphorus distance is shorter than systems where the boron atom is surrounded by groups other than hydrogen atoms. The analysis of the CSD data has shown that FLPs have a tendency for the longest boron-phosphorus distance among all phosphine-borane pairs, as well as different other geometrical parameters. The results show that most of the frustrated phosphine-borane pairs found in crystal structures are bridged ones. The minority of non-bridged FLP structures contain, beside phosphorus and boron atoms, other heteroatoms (O, N, S for instance).
Collapse
Affiliation(s)
- Milan R Milovanović
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia
| | - Jelena M Andrić
- Innovation Center, Department of Chemistry, Studentski trg 12-16, Belgrade, 11000, Serbia
| | - Vesna B Medaković
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia
| | - Jean Pierre Djukic
- Institut de Chimie de Strasbourg, UMR 7177 CNRS, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg, 67000, France
| | - Sneǽana D Zarić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia
| |
Collapse
|
3
|
|
4
|
Medaković VB, Bogdanović GA, Milčić MK, Janjić GV, Zarić SD. CH/π interactions in metal–porphyrin complexes with pyrrole and chelate rings as hydrogen acceptors. J Inorg Biochem 2012; 117:157-63. [DOI: 10.1016/j.jinorgbio.2012.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 09/01/2012] [Accepted: 09/01/2012] [Indexed: 10/27/2022]
|
5
|
Mahadevi AS, Sastry GN. Cation-π interaction: its role and relevance in chemistry, biology, and material science. Chem Rev 2012; 113:2100-38. [PMID: 23145968 DOI: 10.1021/cr300222d] [Citation(s) in RCA: 728] [Impact Index Per Article: 60.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- A Subha Mahadevi
- Molecular Modeling Group, CSIR-Indian Institute of Chemical Technology Tarnaka, Hyderabad 500 607, Andhra Pradesh, India
| | | |
Collapse
|
6
|
|
7
|
Sredojević DN, Vojislavljević DZ, Tomić ZD, Zarić SD. Parallel stacking interactions in square-planar transition-metal complexes containing fused chelate and C6-aromatic rings. ACTA CRYSTALLOGRAPHICA SECTION B: STRUCTURAL SCIENCE 2012; 68:261-5. [DOI: 10.1107/s0108768112012281] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 03/21/2012] [Indexed: 11/10/2022]
Abstract
Stacking interactions in the crystal structures of square-planar transition metal complexes from the Cambridge Structural Database with five- and six-membered chelate rings fused with C6-arom rings (arom = aromatic) were analyzed. The distribution of distances between the closest C6-arom–C6-arom and C6-arom–chelate contacts shows that in a large fraction of the intermolecular interactions the C6-arom ring of one molecule is closer to the chelate than to the C6-arom ring of the other molecule. These results indicate a possible preference of the C6-arom ring to form stacking contacts with the chelate rings. The preference is ubiquitous and does not depend on the metal type.
Collapse
|
8
|
Premkumar JR, Vijay D, Sastry GN. The significance of the alkene size and the nature of the metal ion in metal–alkene complexes: a theoretical study. Dalton Trans 2012; 41:4965-75. [DOI: 10.1039/c2dt30119a] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
9
|
Cysewski P, Szefler B. Environment influences on the aromatic character of nucleobases and amino acids. J Mol Model 2010; 16:1709-20. [PMID: 20668897 PMCID: PMC2949574 DOI: 10.1007/s00894-010-0806-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 07/09/2010] [Indexed: 11/29/2022]
Abstract
Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited in public databases at the finest resolution available (≤ 1.5 Å), or from structures resulting from full gradient geometry optimization in a hybrid QM/MM approach. Significant environmental effects imposing alterations of HOMA values were noted for all aromatic rings analysed. Furthermore, even extra fine resolution (≤ 1.0 Å) is not sufficient for direct estimation of HOMA values based on Cartesian coordinates provided by PDB files. The values of mean bond errors seem to be much higher than the 0.05 Å often reported for PDB files. The use of quantum chemistry geometry optimization is strongly advised; even a simple QM/MM model comprising only the aromatic substructure within the QM region and the rest of biomolecule treated classically within the MM framework proved to be a promising means of describing aromaticity inside native environments. According to the results presented, three consequences of the interaction with the environment can be observed that induce changes in structural and magnetic indices of aromaticity. First, broad ranges of HOMA or NICS values are usually obtained for different conformations of nearest neighborhood. Next, these values and their means can differ significantly from those characterising isolated monomers. The most significant increase in aromaticities is expected for the six-membered rings of guanine, thymine and cytosine. The same trend was also noticed for all amino acids inside proteins but this effect was much smaller, reaching the highest value for the five-membered ring of tryptophan. Explicit water solutions impose similar changes on HOMA and NICS distributions. Thus, environment effects of protein, DNA and even explicit water molecules are non-negligible sources of aromaticity changes appearing in the rings of nucleobases and aromatic amino acids residues.
Collapse
Affiliation(s)
- Piotr Cysewski
- Department of Physical Chemistry, Collegium Medicum, Nicolaus Copernicus University, Kurpińskiego 5, 85-950, Bydgoszcz, Poland.
| | | |
Collapse
|
10
|
Suresh CH, Mohan N, Vijayalakshmi KP, George R, Mathew JM. Typical aromatic noncovalent interactions in proteins: A theoretical study using phenylalanine. J Comput Chem 2009; 30:1392-404. [DOI: 10.1002/jcc.21162] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
11
|
Soteras I, Orozco M, Luque FJ. Induction effects in metal cation–benzene complexes. Phys Chem Chem Phys 2008; 10:2616-24. [DOI: 10.1039/b719461g] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
12
|
Qu X, Wang X, Zhu D. The partitioning of PAHs to egg phospholipids facilitated by copper and proton binding via cation-pi interactions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:8321-8327. [PMID: 18200858 DOI: 10.1021/es0718117] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The partitioning to lipid-containing solids (cell membranes, natural organic matters) plays an important role in the fate of organic pollutants. We herein studied sorption of a series of aromatic compounds from aqueous solution to gel-phase egg phospholipids. The regression line describing the free-energy relationship between lipid-water distribution coefficient (Kd) and n-octanol-water partition coefficient (K(OW)) for the high-polar compounds (phenolics, dinitrobenzene, trinitrobenzene) is displaced upward relative to the low-polar compounds (chlorobenzenes, polycyclic aromatic hydrocarbons (PAHs), nitrobenzene, dichlorobenzonitrile), suggesting additive polar extra-interactions besides hydrophobic effects in sorption. Binding of Cu2+ or decreasing pH increases sorption of the three and four-ring PAHs but not the rest compounds. These results led us to propose a specific sorption mechanism, cation-pi bonding between PAHs and complexed metal ions or protonated amine groups of phospholipids. The Cu(2+)-PAH complexation in solution was supported by the observation that PAHs enhance the saturated solubility of CuSO4 in chloroform, and the enhancement correlates with pi-donor strength of PAH (pyrene > phenanthrene > naphthalene). The electron coupling between the protonated amine groups of phospholipids and PAHs in chloroform was verified by the electronic deshielding-induced downfield chemical shifts of phenanthrene at low pH in the 1H NMR spectrum.
Collapse
Affiliation(s)
- Xiaolei Qu
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Jiangsu 210093, PR China
| | | | | |
Collapse
|
13
|
Żurowska B, Mroziński J, Ślepokura K. Structure and magnetic properties of a double out-of-plane carboxylato-bridged Cu(II) compound with pyridine-2-carboxylate. Polyhedron 2007. [DOI: 10.1016/j.poly.2007.03.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
14
|
Milcić MK, Ostojić BD, Zarić SD. Are Chelate Rings Aromatic? Calculations of Magnetic Properties of Acetylacetonato and o-Benzoquinonediimine Chelate Rings. Inorg Chem 2007; 46:7109-14. [PMID: 17655219 DOI: 10.1021/ic062292w] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aromaticity of the chelate rings of acetylacetonato (acac) and o-benzoquinonediimine (bqdi) ligands was investigated theoretically by calculating nucleus-independent chemical shifts (NICS). The calculations were done for the complexes with various metals and various other ligands. The results show that acac chelate rings in none of the complexes satisfy this magnetic criterion for aromaticity. According to the results for bqdi chelate rings, there is only the Ru2+-bqdi chelate ring with large negative NICS values, indicating possible aromaticity by magnetic criterion.
Collapse
Affiliation(s)
- Milos K Milcić
- Department of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | | | | |
Collapse
|
15
|
Milcic MK, Medaković VB, Sredojević DN, Juranić NO, Zarić SD. Electron delocalization mediates the metal-dependent capacity for CH/pi interactions of acetylacetonato chelates. Inorg Chem 2007; 45:4755-63. [PMID: 16749840 DOI: 10.1021/ic051926g] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CH/pi interactions between the coordinated acetylacetonato ligand and phenyl rings were analyzed in the crystal structures from the Cambridge Structural Database and by quantum chemical calculations. The acetylacetonato ligand may engage in two types of interactions: it can be hydrogen atom donor or acceptor. The analysis of crystal structures and calculations show that interactions with the acetylacetonato ligand acting as hydrogen atom donor depend on the metal in an acetylacetonato chelate ring; the chelate rings with soft metals make stronger interactions. The same trend was not observed in the interactions where the acetylacetonato chelate ring acts as the hydrogen atom acceptor.
Collapse
Affiliation(s)
- Milos K Milcic
- Department of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia and Montenegro
| | | | | | | | | |
Collapse
|
16
|
Xiao L, Qu X, Zhu D. Biosorption of nonpolar hydrophobic organic compounds to Escherichia coli facilitated by metal and proton surface binding. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:2750-5. [PMID: 17533834 DOI: 10.1021/es062343o] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We observed that the presence of transition metal ion, Ag+, Cu2+, or Fe3+, at a concentration of 3 mg L(-1) increases sorption of two nonpolar hydrophobic organic compounds (HOCs), phenanthrene (PHEN), and 1,2,4,5-tetrachlorobenzene (TeCB) by 1.5-4 times to Gram-negative bacteria Escherichia coli. Complexation of transition metals with the deprotonated functional groups (mainly carboxyl) of bacterial cell walls neutralizes the negative charge, making the bacterial surface less hydrophilic and enhancing hydrophobic partition of HOCs. This is evidenced by the fact that the zeta potential (zeta) value of bacteria becomes less negative when a transition metal is present. Furthermore, the observed higher sorption of PHEN than TeCB at low pH (3.8) cannot be fully explained by the pH-dependent hydrophobic effects. The results led us to propose two specific sorption mechanisms for pi-donor compounds: cation-pi interactions with protonated amines and pi H-bonding with protonated carboxyls. The biosorption of PHEN was best described as pi-donor compared to the biosorption of TeCB considered non-pi-donor. Results of the present study highlight that the presence of coexisting transition metals and changes on pH have a major effect on the biosorption of nonpolar HOCs.
Collapse
Affiliation(s)
- Lin Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Jiangsu 210093, PR China
| | | | | |
Collapse
|
17
|
Influence of metal and ligand types on stacking interactions of phenyl rings with square-planar transition metal complexes. OPEN CHEM 2007. [DOI: 10.2478/s11532-006-0068-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AbstractIn order to find out whether metal type influences the stacking interactions of phenyl rings in square-planar complexes, geometrical parameters for Cu, Ni, Pd and Pt complexes, with and without chelate rings, were analyzed and compared. By searching the Cambridge Structural Database, 220 structures with Cu complexes, 211 with Ni complexes, 285 with Pd complexes, and 220 with Pt complexes were found. The results show that the chelate ring has a tendency to make the stacking interaction with the phenyl ring independent of metal type in the chelate ring. However, there are some differences among metals for complexes without a chelate ring. There are a number of structures containing Pd and Pt complexes, without chelate rings, that have short carbon-metal distances and parallel orientations of the phenyl ring with respect to the coordination plane. It was found that some of these complexes have a common fragment, CN, as a part of the ligands. This indicates that the CN supports stacking interactions of square planar complexes with the phenyl ring.
Collapse
|
18
|
Sredojević D, Bogdanović GA, Tomić ZD, Zarić SD. Stacking vs. CH–π interactions between chelate and aryl rings in crystal structures of square-planar transition metal complexes. CrystEngComm 2007. [DOI: 10.1039/b704302c] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
19
|
CH/π interactions of π-system of acetylacetonato chelate ring: Comparison of CH/π interactions of Ni(II)-acetylacetonato chelate and benzene rings. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2006.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
20
|
Kalinowska M, Siemieniuk E, Kostro A, Lewandowski W. The application of Aj, BAC, I6, HOMA indexes for quantitative determination of aromaticity of metal complexes with benzoic, salicylic, nicotinic acids and benzene derivatives. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.theochem.2006.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
21
|
Medaković VB, Milcić MK, Bogdanović GA, Zarić SD. C-H. . .pi interactions in the metal-porphyrin complexes with chelate ring as the H acceptor. J Inorg Biochem 2005; 98:1867-73. [PMID: 15522414 DOI: 10.1016/j.jinorgbio.2004.08.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 07/27/2004] [Accepted: 08/09/2004] [Indexed: 11/22/2022]
Abstract
Specific C-H. . .pi interactions with the pi-system of porphyrinato chelate ring were found in crystal structures of transition metal complexes from the Cambridge Structural Database and statistical analysis of geometrical parameters for intramolecular and intermolecular interactions was done. By density functional theory calculations on a model system it was evaluated that an interaction energy is above 1.5 kcal/mol and that the strongest interaction occurs when the distance between hydrogen atom and the center of the chelate ring is 2.6 A. This prediction is in good agreement with the distances for intermolecular interactions found in the crystal structures. In many cases the intramolecular interaction distances are much shorter than 2.6 A, and these short distances are caused by geometrical constrains. The C-H. . .pi interactions with chelate ring of porphyrinato ligand can influence the structure, contribute to its stability, and play some role in the function of biomolecules with metalo porphyrins.
Collapse
Affiliation(s)
- Vesna B Medaković
- Department of Chemistry, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia and Montenegro
| | | | | | | |
Collapse
|
22
|
NH···π Interactions Stabilize the Most-Hindered Rotamer of the(S)-Tyrosinato Side Group in Bis[(S)-tyrosinato](diamine)cobalt(III) Complexes: An NMR Spectroscopic and DFT Study. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400873] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Galstyan AS, Zarić SD, Knapp EW. Computational studies on imidazole heme conformations. J Biol Inorg Chem 2005; 10:343-54. [PMID: 15843984 DOI: 10.1007/s00775-005-0642-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Accepted: 03/09/2005] [Indexed: 11/25/2022]
Abstract
Density functional theory computations of heme with ionized propionic acid groups, axially coordinated with two imidazoles, were performed for different mutual orientations of the imidazole planes. Environmental influences from water or protein were considered with a continuum dielectric medium by solving the Poisson equation. In vacuum, optimized geometries yielded imidazole-heme conformations where the NH groups of imidazoles are oriented toward the heme propionic groups in agreement with data from crystal structures of heme proteins. Conformational free-energy dependencies of the mutual orientation of axially ligated imidazoles calculated in protein (epsilon=10) and water (epsilon=80) environments confirmed the vacuum results, albeit the energy difference between the preferred and the 180 degrees opposite orientations of the imidazole ligand decreased from 3.84 kcal/mol in vacuum to 2.35 and 2.40 kcal/mol in protein and water, respectively. Two main factors determine the imidazole orientation: (1) the direct intramolecular electrostatic interactions of propionic groups with the polar NH groups of imidazole and (2) the electrostatic interaction of the total dipole moment of the imidazole-heme complex with the reaction field. In vacuum, only the first type of interaction is present, while in a dielectric medium the latter effect becomes competitive at high dielectric constant, resulting in a decrease of the orientational preference. Interestingly, the orientational preference of the imidazole axially ligated to heme becomes even more pronounced, if the negatively charged propionates are neutralized by counter charges that mimic salt bridges or protonation of the propionates.
Collapse
Affiliation(s)
- Artur S Galstyan
- Institute of Chemistry, Department of Biology, Chemistry, and Pharmacy, Free University of Berlin, Takustrasse 6, 14195 Berlin, Germany
| | | | | |
Collapse
|
24
|
Milčić MK, Tomić ZD, Zarić SD. Very strong metal ligand aromatic cation-π interactions in transition metal complexes: intermolecular interaction in tetraphenylborate salts. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.06.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
25
|
Hu J, Barbour LJ, Gokel GW. Cation-π Interactions Between Alkali Metal Cations and Neutral Double Bonds. ACTA ACUST UNITED AC 2004. [DOI: 10.1135/cccc20041050] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Two-armed lariat ethers having double bonds present in their side arms form stable complexes with sodium and potassium cations. When the double bonds are positioned appropriately, cation-π interactions are observed between the neutral double bonds and the macroring- bound cation as demonstrated by X-ray crystallography.
Collapse
|
26
|
Zhu D, Herbert BE, Schlautman MA, Carraway ER. Characterization of cation-pi interactions in aqueous solution using deuterium nuclear magnetic resonance spectroscopy. JOURNAL OF ENVIRONMENTAL QUALITY 2004; 33:276-284. [PMID: 14964382 DOI: 10.2134/jeq2004.2760] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Chemical interactions of aromatic organic contaminants control their fate, transport, and toxicity in the environment. Recent molecular modeling studies have suggested that strong interactions can occur between the pi electrons of aromatic molecules and metal cations in aqueous solutions and/or on mineral surfaces, and that such interactions may be important in some environmental systems. However, spectroscopic evidence for these so-called cation-pi interactions has been extremely limited to date. In this paper, cation-pi interactions in aqueous salt solutions were characterized via 2H nuclear magnetic resonance (NMR) spin-lattice relaxation times (T1) and calculations of molecular correlation times (tau(c)) for a series of perdeuterated (d6-benzene) benzene-cation complexes. The T1 values for d6-benzene decreased with increasing concentrations of LiCl, NaCl, KCl, RbCl, CsCl, and AgNO3, with the largest effects observed in the AgNO3 and CsCl solutions. Upon normalizing tau(c) values by solution viscosity effects, an overall affinity trend of Ag+ >> Cs+ > K+ > Rb+ > Na+ > Li+ was derived for the d6-benzene-cation complexes. The ability of Ag+ to complex d6-benzene was significantly reduced upon addition of NH3, which strongly coordinates Ag+ at high pH. Results with d6-benzene, d8-naphthalene, d2-dichloromethane, and d12-cyclohexane in 0.1 M methanolic salt solutions confirmed that spin-lattice relaxation rates are characterizing cation-pi interactions. The relatively strong cation-pi bonding observed between Ag+ and aromatic hydrocarbons probably results from covalent interactions between the aromatic pi electrons and the d orbitals of Ag+, in addition to the normal electrostatic interaction.
Collapse
Affiliation(s)
- Dongqiang Zhu
- Department of Civil Engineering, Texas A&M University, College Station, TX 77840, USA.
| | | | | | | |
Collapse
|
27
|
Medaković V, Zarić SD. Theoretical study on orientations of axially coordinated imidazoles in model systems of cytochromes. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(03)00086-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
28
|
|
29
|
Tomić Z, Leovac V, Pokorni SV, Zobel D, Zarić S. Crystal Structure of Bis[acetone-1-naphthoylhydrazinato(−1)]copper(II) and Investigations of Intermolecular Interactions. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200390158] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
30
|
Bogdanović G, Biré AD, Zarić S. Evidence Based on Crystal Structures and Calculations of a C−H···π Interaction Between an Organic Moiety and a Chelate Ring in Transition Metal Complexes. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200207)2002:7<1599::aid-ejic1599>3.0.co;2-i] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
31
|
Milčić M, Zarić S. Intramolecular Metal Ligand Aromatic Cation−π Interactions in Crystal Structures of Transition Metal Complexes. Eur J Inorg Chem 2001. [DOI: 10.1002/1099-0682(200108)2001:8<2143::aid-ejic2143>3.0.co;2-c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
32
|
Bogdanović GA, Medaković VB, Vojinović LS, Češljević VI, Leovac VM, Spasojević-de Biré A, Zarić SD. Transition metal complexes with thiosemicarbazide-based ligands. Part XLI. Two crystal structures of cobalt(III) complexes with salicylaldehyde S-methylisothiosemicarbazone and theoretical study on orientations of coordinated pyridines. Polyhedron 2001. [DOI: 10.1016/s0277-5387(01)00819-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
33
|
Zarić SD. Theoretical study of cation–π interactions of the metal complex cation, [Co(NH3)6]3+, with ethylene and acetylene. Chem Phys 2000. [DOI: 10.1016/s0301-0104(00)00074-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|