scholarly journals Raman and XANES Spectroscopic Study of the Influence of Coordination Atomic and Molecular Environments in Biomimetic Composite Materials Integrated with Dental Tissue

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3099
Author(s):  
Dmitry Goloshchapov ◽  
Nikita Buylov ◽  
Anna Emelyanova ◽  
Ivan Ippolitov ◽  
Yuri Ippolitov ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Organic Matrix ◽  
Local Environment ◽  
Dental Composite ◽  
Energy Structure ◽  
Dental Tissue ◽  
Calcium Atom ◽  
Tissue Samples ◽  
Edge Structure ◽  
Coordination Environment

In this work, for the first time, the influence of the coordination environment as well as Ca and P atomic states on biomimetic composites integrated with dental tissue was investigated. Bioinspired dental composites were synthesised based on nanocrystalline calcium carbonate-substituted hydroxyapatite Ca4ICa6IIPO46−xCO3x+yOH2−y (nano-cHAp) obtained from a biogenic source and a set of polar amino acids that modelled the organic matrix. Biomimetic composites, as well as natural dental tissue samples, were investigated using Raman spectromicroscopy and synchrotron X-ray absorption near edge structure (XANES) spectroscopy. Molecular structure and energy structure studies revealed several important features related to the different calcium atomic environments. It was shown that biomimetic composites created in order to reproduce the physicochemical properties of dental tissue provide good imitation of molecular and electron energetic properties, including the carbonate anion CO32− and the atomic Ca/P ratio in nanocrystals. The features of the molecular structure of biomimetic composites are inherited from the nano-cHAp (to a greater extent) and the amino acid cocktail used for their creation, and are caused by the ratio between the mineral and organic components, which is similar to the composition of natural enamel and dentine. In this case, violation of the nano-cHAp stoichiometry, which is the mineral basis of the natural and bioinspired composites, as well as the inclusion of different molecular groups in the nano-cHAp lattice, do not affect the coordination environment of phosphorus atoms. The differences observed in the molecular and electron energetic structures of the natural enamel and dentine and the imitation of their properties by biomimetic materials are caused by rearrangement in the local environment of the calcium atoms in the HAp crystal lattice. The surface of the nano-cHAp crystals in the natural enamel and dentine involved in the formation of bonds with the organic matrix is characterised by the coordination environment of the calcium atom, corresponding to its location in the CaI position—that is, bound through common oxygen atoms with PO4 tetrahedrons. At the same time, on the surface of nano-cHAp crystals in bioinspired dental materials, the calcium atom is characteristically located in the CaII position, bound to the hydroxyl OH group. The features detected in the atomic and molecular coordination environment in nano-cHAp play a fundamental role in recreating a biomimetic dental composite of the natural organomineral interaction in mineralised tissue and will help to find an optimal way to integrate the dental biocomposite with natural tissue.

Electron energy-loss near-edge structure in silicate minerals

1992 ◽  
Vol 50 (2) ◽  
pp. 1258-1259
Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson
Keyword(s):  
Solid State ◽  
Energy Loss ◽  
Electron Energy ◽  
State Energy ◽  
Local Environment ◽  
Edge Structure ◽  
Silicate Minerals ◽  
Two Samples ◽  
Electron Energy Loss ◽  
Careful Processing

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.

The Use of ELNES for Microanalysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 664-665
Author(s):  
A.J. Craven ◽  
M. MacKenzie
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Analytical Electron Microscopy ◽  
Local Environment ◽  
Edge Structure ◽  
Similar Shape ◽  
Analytical Electron ◽  
Electron Energy Loss ◽  
Combining Information

The performance of many materials systems depends on our ability to control the distribution of atoms on a nanometre or sub-nanometre scale within those systems. This is as true for steels as it is for semiconductors. A key requirement for improving their performance is the ability to determine the distribution of the elements resulting from processing the material under a given set of conditions. Analytical electron microscopy (AEM) provides a range of powerful techniques with which to investigate this distribution. By combining information from different techniques, many of the ambiguities of interpretation of the data from an individual technique can be eliminated. The electron energy loss near edge structure (ELNES) present on an ionisation edge in the electron energy loss spectrum reflects the local structural and chemical environments in which the particular atomic species occurs. Thus it is a useful contribution to the information available. Since a similar local environment frequently results in a similar shape, ELNES is useful as a “fingerprint”.

scholarly journals Di-μ-chlorido-bis{bis[N,N-bis(trimethylsilyl)amido]titanium(III)}

IUCrData ◽  
2017 ◽  
Vol 2 (10) ◽  
Author(s):  
Coralie C. Quadri ◽  
Karl W. Törnroos ◽  
Erwan Le Roux
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Coordination Environment ◽  
Cl Atoms

The molecular structure of the title compound, [Ti2Cl2(C6H18NSi2)4], shows a binuclear motif of TiIIIatoms, formulated as [Ti(μ-Cl)(N(SiMe3)2)2]2, with two μ-Cl atoms bridging two ((Me3Si)2N)2Ti moieties. The coordination environment of both central TiIIIatoms is distorted tetrahedral, with a nearly planar four-membered Ti2Cl2core [Ti—Cl—Ti—Cl = 2.796 (15)°].

scholarly journals Crystal structure of aquatris{μ-N-[bis(diethylamino)phosphoryl]-2,2,2-trichloroacetamidato-κ3O,O′:O}calciumsodium

2016 ◽  
Vol 72 (12) ◽  
pp. 1683-1686 ◽  
Author(s):  
Iuliia Shatrava ◽  
Kateryna Gubina ◽  
Vladimir Ovchynnikov ◽  
Viktoriya Dyakonenko ◽  
Vladimir Amirkhanov
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Water Molecules ◽  
Carbonyl Groups ◽  
Coordination Environment ◽  
Distorted Octahedral Coordination ◽  
Distorted Octahedral ◽  
Phosphoryl Groups ◽  
Cl Atoms ◽  
Distorted Octahedral Coordination Environment

In the molecular structure of the title compound, [CaNa(C10H20Cl3N3O2P)3(H2O)], the Ca2+ion has a slightly distorted octahedral coordination environment defined by six O atoms which belong to the carbonyl and phosphoryl groups of the three coordinating ligands. Two Cl atoms of CCl3groups and four O atoms form the coordination environment of the Na+ion: three from the carbonyl groups of ligands and one O atom from a coordinating water molecule. In the crystal, the bimetallic complexes are assembled into chains along thec-axis directionviaO—H...O hydrogen bonds that involve the coordinating water molecules and the phosphoryl groups.

A Novel Methylene Dithioether as a Ligand: Synthesis and Molecular Structure of a Zinc(II) Complex with N4S2 Coordination Environment

2003 ◽  
Vol 58 (10) ◽  
pp. 1027-1029 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Christoph Jocher ◽  
Henning Schröder
Keyword(s):  
Molecular Structure ◽  
Diffraction Study ◽  
Aluminum Hydroxide ◽  
Zinc Atom ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Octadentate Ligand ◽  
Ligand Synthesis ◽  
Perchlorate Hexahydrate

The octadentate ligand [N(CH2CH2NH2)(CH2CH2CH2OH)(CH2CH2S)]2CH2, (NNOS-232)2CH2, was synthesized accidentally by the reaction of the unsymmetrically substituted tripod [N(CH2CH2NH2)(CH2CH2CH2OH)(CH2CH2SH)], NNOS-232, with dichloromethane in the presence of aluminum hydroxide. Ligand (NNOS-232)2CH2 was reacted with zinc bis(perchlorate) hexahydrate to yield the complex [Zn((NNOS-232)2CH2)](ClO4)2 1 exhibiting a distorted octahedrally coordinated zinc atom in an N4S2 coordination environment, as shown by an X-ray diffraction study.

scholarly journals The Mineral Phase of Calcified Cartilage: Its Molecular Structure and Interface with the Organic Matrix

2009 ◽  
Vol 96 (8) ◽  
pp. 3372-3378 ◽  
Author(s):  
Melinda J. Duer ◽  
Tomislav Friščić ◽  
Rachel C. Murray ◽  
David G. Reid ◽  
Erica R. Wise
Keyword(s):  
Molecular Structure ◽  
Organic Matrix ◽  
Mineral Phase ◽  
Calcified Cartilage

scholarly journals Crystal structure of an eight-coordinate terbium(III) ion chelated byN,N′-bis(2-hydroxybenzyl)-N,N′-bis(pyridin-2-ylmethyl)ethylenediamine (bbpen2−) and nitrate

2015 ◽  
Vol 71 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Thaiane Gregório ◽  
André Luis Rüdiger ◽  
Giovana G. Nunes ◽  
Jaísa F. Soares ◽  
David L. Hughes
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Rotation Axis ◽  
Nitrate Anion ◽  
Coordination Geometry ◽  
Two Dimensional ◽  
Coordination Environment ◽  
Dimensional Network ◽  
Benzene Rings ◽  
Unique Part

The reaction of terbium(III) nitrate pentahydrate in acetonitrile withN,N′-bis(2-hydroxybenzyl)-N,N′-bis(pyridin-2-ylmethyl)ethylenediamine (H2bbpen), previously deprotonated with triethylamine, produced the mononuclear compound [N,N′-bis(2-oxidobenzyl-κO)-N,N′-bis(pyridin-2-ylmethyl-κN)ethylenediamine-κ2N,N′](nitrato-κ2O,O′)terbium(III), [Tb(C28H28N4O2)(NO3)]. The molecule lies on a twofold rotation axis and the TbIIIion is eight-coordinate with a slightly distorted dodecahedral coordination geometry. In the symmetry-unique part of the molecule, the pyridine and benzene rings are both essentially planar and form a dihedral angle of 61.42 (7)°. In the molecular structure, the N4O4coordination environment is defined by the hexadentate bbpen ligand and the bidentate nitrate anion. In the crystal, a weak C—H...O hydrogen bond links molecules into a two-dimensional network parallel to (001).

scholarly journals Crystal structure oftrans-(1,8-dibutyl-1,3,6,8,10,13-hexaazacyclotetradecane-κ4N3,N6,N10,N13)bis(isonicotinato-κO)nickel(II) determined from synchrotron data

2016 ◽  
Vol 72 (2) ◽  
pp. 223-225 ◽  
Author(s):  
Jong Won Shin ◽  
Dae-Woong Kim ◽  
Dohyun Moon
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Equatorial Plane ◽  
Self Assembly ◽  
Title Compound ◽  
Isonicotinic Acid ◽  
Inversion Center ◽  
Coordination Environment ◽  
Distorted Octahedral

The title compound, [Ni(C6H4NO2)2(C16H38N6)], was prepared through self-assembly of a nickel(II) azamacrocyclic complex with isonicotinic acid. The NiIIatom is located on an inversion center and exhibits a distorted octahedral N4O2coordination environment, with the four secondary N atoms of the azamacrocyclic ligand in the equatorial plane [average Ni—Neq= 2.064 (11) Å] and two O atoms of monodentate isonicotinate anions in axial positions [Ni—Oax= 2.137 (1) Å]. Intramolecular N—H...O hydrogen bonds between one of the secondary amine N atoms of the azamacrocyclic ligand and the non-coordinating carboxylate O atom of the anion stabilize the molecular structure. Intermolecular N—H...N hydrogen bonds, as well as π–π interactions between neighbouring pyridine rings, give rise to the formations of supramolecular ribbons extending parallel to [001].

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