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Journal ArticleDOI

A titanium salicylate, Na4[Ti(C7H4O3)3]2·11H2O

01 Aug 2005-Acta Crystallographica Section E-structure Reports Online (International Union of Crystallography)-Vol. 61, Iss: 8, pp 1495-1497

AbstractThe title compound, tetra­sodium bis­[tris­(salicylato­titanate(IV)] undeca­hydrate, Na4[Ti(C7H4O3)3]2·11H2O, crystallizes with two titanium salicylate complex ions, four sodium ions and 11 water mol­ecules in the asymmetric unit. One water O atom is disordered over two positions, having 0.74 (5) and 0.26 (5) occupancy. Both Ti atoms and three sodium ions adopt a distorted octa­hedral coordination by O atoms. The fourth sodium ion has a distorted trigonal–bipyramidal coordination by oxygen, sharing one edge with a sodium coordination octa­hedron.

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Citations
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Journal ArticleDOI
TL;DR: By closely examining the biological use of TiO2 and the influence of biomolecules on its stability and solubility, the reactivity of the material is reassessed in the presence and absence of UV energy.
Abstract: Titanium is one of the most abundant elements in the earth’s crust and while there are many examples of its bioactive properties and use by living organisms, there are few studies that have probed its biochemical reactivity in physiological environments. In the cosmetic industry, TiO2 nanoparticles are widely used. They are often incorporated in sunscreens as inorganic physical sun blockers, taking advantage of their semiconducting property, which facilitates absorbing ultraviolet (UV) radiation. Sunscreens are formulated to protect human skin from the redox activity of the TiO2 nanoparticles (NPs) and are mass-marketed as safe for people and the environment. By closely examining the biological use of TiO2 and the influence of biomolecules on its stability and solubility, we reassess the reactivity of the material in the presence and absence of UV energy. We also consider the alarming impact that TiO2 NP seepage into bodies of water can cause to the environment and aquatic life, and the effect that it can have on human skin and health, in general, especially if it penetrates into the human body and the bloodstream.

24 citations

Journal ArticleDOI
TL;DR: Based on its chemical similarities with Fe, the biological coordination chemistry of Fe(III) and Ti(IV) is compared and it is hypothesized that Ti( IV) can bind to similar intracellular biomolecules and inhibit Fe bioavailability.
Abstract: Despite its natural abundance and widespread use as food, paint additive, and in bone implants, no specific biological function of titanium is known in the human body. High concentrations of Ti(IV) could result in cellular toxicity, however, the absence of Ti toxicity in the blood of patients with titanium bone implants indicates the presence of one or more biological mechanisms to mitigate toxicity. Similar to Fe(III), Ti(IV) in blood binds to the iron transport protein serum transferrin (sTf), which gives credence to the possibility of its cellular uptake mechanism by transferrin-directed endocytosis. However, once inside the cell, how sTf bound Ti(IV) is released into the cytoplasm, utilized, or stored remain largely unknown. To explain the molecular mechanisms involved in Ti use in cells we have drawn parallels with those for Fe(III). Based on its chemical similarities with Fe(III), we compare the biological coordination chemistry of Fe(III) and Ti(IV) and hypothesize that Ti(IV) can bind to similar intracellular biomolecules. The comparable ligand affinity profiles suggest that at high Ti(IV) concentrations, Ti(IV) could compete with Fe(III) to bind to biomolecules and would inhibit Fe bioavailability. At the typical Ti concentrations in the body, Ti might exist as a labile pool of Ti(IV) in cells, similar to Fe. Ti could exhibit different types of properties that would determine its cellular functions. We predict some of these functions to mimic those of Fe in the cell and others to be specific to Ti. Bone and cellular speciation and localization studies hint toward various intracellular targets of Ti like phosphoproteins, DNA, ribonucleotide reductase, and ferritin. However, to decipher the exact mechanisms of how Ti might mediate these roles, development of innovative and more sensitive methods are required to track this difficult to trace metal in vivo.

20 citations


References
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Journal ArticleDOI
Abstract: A Fortran program has been developed for the reduction of single-crystal diffraction data from a sequence of adjacent rotation pictures recorded at a fixed X-ray wavelength by an electronic area detector. The electronic pictures (data frames) covering the first 5° of crystal rotation are used to locate strong diffraction spots and to estimate the background. The orientation of the crystal is derived automatically from the list of observed spots and all parameters describing the diffraction pattern are refined. The only input required from the user is the specification of the space group, approximate cell dimensions and detector setting. When the initialization step is finished the program goes back to the first picture and evaluates all data frames in the order they arrive from the measurement. Each element of an electronic picture (pixel) is labelled by the indices of the nearest reflection using the current refined parameters describing the diffraction geometry. If the pixels close to its nearest reflection the counts contribute to the three-dimensional profile; otherwise the counts are used to update the background. Each profile is represented as if the reflection had followed the shortest path through the Ewald sphere and had been recorded on the surface of the sphere. Reflections close to the Ewald sphere are kept in a hash table to allow rapid access for updating the profiles. Reflections which have completely passed through the Ewald sphere are removed from the table and saved for further processing. Intensities are estimated by fitting their profiles to an average shape learned from strong neighbouring reflections. Smoothly varying scaling factors are applied to the Lp-corrected intensities which minimize discrepancies between symmetry-related reflections and fit to a reference data set if available.

1,512 citations


"A titanium salicylate, Na4[Ti(C7H4O..." refers methods in this paper

  • ...Most water H atoms were located in a difference Fourier synthesis Data collection: XDS (Kabsch, 1988); cell refinement: XDS; data reduction: XDS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: PLATON (Spek, 2003)....

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  • ...Most water H atoms were located in a difference Fourier synthesis Data collection: XDS (Kabsch, 1988); cell refinement: XDS; data reduction: XDS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics:…...

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Journal ArticleDOI

132 citations


"A titanium salicylate, Na4[Ti(C7H4O..." refers background in this paper

  • ...O distances are similar to those in salicylic acid itself (Sundaralingam & Jensen, 1965; Cochran, 1953)....

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  • ...Corresponding angles with values of 117 (Cochran, 1953) and 116 (Sundaralingam & Jensen, 1965) are found in salicylic acid....

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Journal ArticleDOI
TL;DR: The compositional and structural parameters from the single crystal studies indicate that complexes 2 and 3 may represent sequential steps in a ligand exchange process between the two metal species, while the reactivity patterns that were observed provide clues about the solution state structure of bismuth(III) salicylate itself.
Abstract: The reaction of a 1:2 mixture of bismuth(III) salicylate with titanium(IV) isopropoxide in refluxing toluene has been investigated and found to proceed with ligand exchange to produce the new heter...

49 citations


"A titanium salicylate, Na4[Ti(C7H4O..." refers background in this paper

  • ...O distances are found in many recently determined crystal structures of titanium complexes (Honda et al., 2003; Thurston et al., 2004)....

    [...]

Journal ArticleDOI
TL;DR: Improvement in the various epidermal compartments was the most prominent finding at the RA-treated site, and RA had a beneficial impact upon the aging epidermis.
Abstract: Background: Studies comparing purported antiaging compounds are rare. Objective: To compare in a randomized, placebo-controlled double-blind study 10% glycolic ac

31 citations


"A titanium salicylate, Na4[Ti(C7H4O..." refers background in this paper

  • ...Salicylic acid is also known to improve skin thickness, skin barrier functions, collagen production and cell renewal (Pierard et al., 1999)....

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Journal ArticleDOI
TL;DR: A new class of achiral ligands with atropisomeric conformations has been coordinated to titanium(IV), consisting of ortho-hydroxy benzamide derivatives which are deprotonated on reaction with titanium tetraisopropoxide to furnish Ti(L)(2)(O-iPr)(2) complexes (L=ortho-phenoxy benzamide).
Abstract: A new class of achiral ligands with atropisomeric conformations has been coordinated to titanium(IV). The ligands are ortho-hydroxy benzamide derivatives which are deprotonated on reaction with titanium tetraisopropoxide to furnish Ti(L)(2)(O-iPr)(2) complexes (L=ortho-phenoxy benzamide). In these octahedral titanium compounds, the ortho-phenoxy benzamide ligands chelate to titanium, bonding through the phenoxide oxygen and the amide carbonyl oxygen. The benzamide ligands adopt atropisomeric conformations with an angle between the aryl and amide groups of approximately 35 degrees. The ligand precursor, ligand, and titanium complexes have been characterized by X-ray crystallography. Only one diastereomer of each titanium complex was observed in the solid state structures.

22 citations


"A titanium salicylate, Na4[Ti(C7H4O..." refers background in this paper

  • ...O distances are found in many recently determined crystal structures of titanium complexes (Honda et al., 2003; Thurston et al., 2004)....

    [...]