Novel structural arrangements for alkoxyalkanol modified titanium tetraisopropoxide [(Ti(OPri)4, TPT] were obtained from stoichiometric reactions between TPT and alkoxyalkanols {HOCH2CH2OR,where R= Me, Et}. All the 1:1, 1:2, 1:3 and 1:4 reactions in refluxing benzene form mononuclear species [(OPri)4-nTi(OC2H4OR)n]. All these compounds can be purified by distillation under reduced pressure. On the basis of IR and NMR (1H &amp;13C) spectral studies all the mononuclear derivatives have been obtained in tetrahedral geometry around titanium atom.

Madhvesh Pathak

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Samuel B

Tummalapalli K

Giri P.V

Koppala S

Bohra R

Kim K.J.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Advanced Materials Research

A new series of moisture resistant metallacyclic titanium(IV) derivatives prepared from 8-hydroxyquinoline of the general formulae [(Q2)Ti{(L1)(L2OR)}] (3a-b, 3d-e), [(Q2)Ti{(L1)(L3)}] (3c and 3f) and [(Q2)Ti(L4)] (3g and 3h) is synthesized by interacting the precursor molecule [(Q2)Ti(OiPr)2] (2) with various 2-heteroaryl methyl ketone oximes and various alkoxyalkanols/2-hydroxypyridine or only with catechol/resorcinol in 1:1:1 or in 1:1 molar ratios in anhydrous boiling toluene (where, HQ = 8-hydroxyquinoline; iPr = isopropyl; L1H = HONC(Me)py-2/HONC(Me)fu-2; L2 = O-CH2-CH2-; R = CH3, C2H5; L3H = 2-hydroxypyridine and L4H = catechol/resorcinol). Stability study revealed that these molecules were stable for a period of 72 h. Mononuclear nature of the complexes was confirmed through mass spectral analysis. Thermogravimetric results explain the multistage fragmentation of the complexes at 900 ºC. NMR, FTIR, and UV-visible spectral data suggested that titanium-ligands attachment is in a hexa-coordinated manner. Additionally, all these molecules were tested for their tumour inhibiting potential against MDA-MB-231 human breast carcinoma cell line. © 2019 Chemical Publishing Co.. All rights reserved.

Fulltext

Asian Journal of Chemistry

A New Series of Moisture Stable Metallacyclic Heteroleptic Titanium(IV) Complexes of 8-Hydroxyquinoline: Synthesis, Characterization, Stability Study and Cytotoxicity Evaluation

Systematic efforts have been made for the synthesis of moisture stable derivatives of titanium (IV) with both nitrogen- and sulfur-based ligands. New heteroleptic titanium (IV) complexes derived from 8-hydroxyquinoline (HQ) of the types [(Q2)Ti{((OiPr)2-n(L1OR1)n-1)(L1OR)}] (3a–3c), [(Q2)Ti(OiPr)2-n(L2)] (3d, 3g), [(Q2)Ti(L1OR)(L2)] (3e, 3f, 3h, 3i) were prepared by treating the precursor [(Q2)Ti(OiPr)2] (2) with different alkoxyalkanols, 2-hydroxypyridine (HPy), and 2-hetroaryl methyl ketone oxime in different mole ratios using anhydrous toluene as solvent (where, n&nbsp;=&nbsp;1–2, HQ&nbsp;=&nbsp;8-HQ, iPr&nbsp;=&nbsp;isopropyl, L1&nbsp;=&nbsp;O–CH2–CH2–, R&nbsp;=&nbsp;CH3, C2H5, R1&nbsp;=&nbsp;C2H5, and L2H&nbsp;=&nbsp;2-HPy, HONC(Me)th-2). Stability study of all these complexes were performed by UV–Visible (UV–Vis) spectroscopy at room temperature and was interpreted on the basis of absorption band arose due to ligand-to-metal charge transfer. All these complexes have good stability against hydrolysis and the shift observed in the absorption band was negligible even after the duration of 72&nbsp;h persistence in 9:1 mixture of dimethyl sulfoxide and water. All the derivatives were characterized by various physicochemical techniques such as NMR (1H, 13C), Elemental Analysis, Mass, Thermogravimetric Analysis (TGA), FT-IR, and UV–Vis spectroscopy. Monomeric nature of all these derivatives was confirmed by mass spectra. TGA describes the multistage decomposition of complexes at 900&nbsp;°C. Elemental analyses results are in agreement with the theoretical values. Other spectral data (NMR, FTIR, and UV–Vis) propose the attachment of titanium and ligands in hexa-coordinated fashion. Further, these were subjected for antibacterial and antifungal evaluation against a panel of microorganisms. Complex 3i has shown better activity compared to all its analogs of this series and it was more potent than the standard drugs gentamicin and fluconazole with minimum inhibitory concentrations of 0.017&nbsp;µM against the Escherichia coli and 0.035&nbsp;µM for Aspergillus niger, respectively.

Medicinal Chemistry Research

Moisture stable heteroleptic titanium (IV) complexes derived from 8-hydroxyquinoline: synthesis, antibacterial, and antifungal studies

A few new and versatile complexes of titanium(IV) derived from 2-hydroxyacetophenone of the types {[(Ap)Ti(OPr i )2-n (L2) n ] (2a, 2e and 2f)}, {[(Ap)Ti(L1OR) (L2)] (2b-2d, 2g-2i)} have been synthesized by the reaction of the precursor [(Ap)Ti(OPr i )2] with different 2-heteroaryl methyl ketone oximes and alkoxyalkanols in various molar ratios in refluxing toluene yielded mono nuclear heteroleptic derivatives, {where, n = 1-2, HAp = 2-hydroxyacetophenone, Pr i = isopropyl, L1 = O-CH 2-CH2-, R = CH3, C2H5, C4H9 and HL2=HONC(Me)py-2, HONC(Me)fu-2}. All these newly synthesized complexes were characterized by elemental analysis, mass, UV, FT-IR and NMR (1H, 13C) spectral studies. The mass spectra of the newly synthesized molecules indicate their monomeric state. Spectral studies suggest the bonding between metal and ligands in a tetra coordinated fashion. Thermogravimetric analyses indicate the multistep decomposition of complexes resulting TiO2 as the end product at 600 C. Antibacterial activities of these complexes were also exercised. Complex 2e is equipotent to the standard drug against Pseudomonas aeruginosa and Escherichia coli. A keen molecular docking study revealed lesser docking scores of some of these complexes than that of the standard drug gentamicin. © 2013 Springer Science+Business Media New York.

Novel heteroleptic complexes of titanium(IV) derived from 2-hydroxyacetophenone: synthesis, characterization, antibacterial and molecular docking studies

Advanced Structured Materials

Recent Trends in Nanomaterials

10.4028/www.scientific.net/amr.584

Reactions of [Ti(OPri)4] with various oximes, in anhydrous refluxing benzene yielded complexes of the type [Ti{OPr i}4-n{L}n], where, n = 1-4 and LH = (CH3)2CNOH (1-4), C9H16CNOH (5-8) and C9H18CNOH (9-12). The compounds were characterized by elemental analyses, molecular weight measurements, FAB-mass, FT-IR and NMR (1H, 13C{1H}) spectral studies. The FAB-mass spectra of mono- (1), and di- (2), (6), (10) substituted products indicate their dimeric nature and that of tri- (3) and tetra- (4), (8) substituted derivatives suggest their monomeric nature. Crystal and molecular structure of [Ti{ONC 10H16}4·2CH2Cl2] (8A) suggests that the oximato ligands bind the metal in a dihapto η2-(N, O) manner, leading to the formation of an eight coordinated species. Thermogravimetric curves of (3), (6) and (10) exhibit multi-step decomposition with the formation of TiO2 as the final product in each case, at 900 °C. Low temperature (∼600 °C) sol-gel transformations of (2), (3), (4), (6), (7) and (8) yielded nano-sized titania (a), (b), (c), (d), (e) and (f), respectively. Formation of anatase phase in all the titania samples was confirmed by powder XRD patterns, FT-IR and Raman spectroscopy. SEM images of (a), (b), (c), (d), (e) and (f) exhibit formation of nano-grains with agglomer like surface morphologies. Compositions of all the titania samples were investigated by EDX analyses. The absorption spectra of the two representative samples, (a) and (f) indicate an energy band gap of 3.17 eV and 3.75 eV, respectively. © 2010 Elsevier Ltd. All rights reserved.

Polyhedron

Chemically modified oximato complexes of titanium(IV) isopropoxide as new precursors for the sol-gel preparation of nano-sized titania: Crystal and molecular structure of [Ti{ONC10H16}4· 2CH2Cl2]

Inorganica Chimica Acta

Syntheses, characterisation and vapour pressure of metallo-organic titanium precursor for MOCVD applications

Two novel dinuclear Ti(IV) complexes of the ligand, 4,4′-methylene-bis (3-hydroxy-2-naphthalene carboxylic acid) (H4L) or pamoic acid having compositions, [(HL)2Ti2(μ-O)(DMF)2]·(DMF)6 (1) and [(L)2Ti2(μ-O)(DMF)2]·(DMF)4(4,4′-Bipy-2H)(H2O), (2) have been synthesized and characterized by analytical and spectral methods and the structure has been established by single crystal XRD. Unlike the reported polymeric structures observed in case of H4L or pamoic acid, the anti-conformation of H4L changes to syn - orientation to avoid poly-metallic complex formation, as noticed in 1 and 2. The dimeric Ti(IV) units stack in the lattice to form helical columns and the space between the adjacent columns is being filled by the solvent molecules in 1 and solvent plus the protonated 4,4′-bipy in the lattice of 2 and thus the neighbor columns are connected through weak interactions. © 2009 Elsevier Ltd. All rights reserved.

Pamoic acid in forming metallo-organic framework: Synthesis, characterization and first crystal structure of a dimeric Ti(IV) complex

Alkoxyalkanol Modified Ti(OCHMe2)4: Synthesis and Characterization of Novel [(OPri)4-nTi (OC2H4OR)n]

Journal	Advanced Materials Research
Publisher	Trans Tech Publications, Ltd.
ISSN	10226680
Open Access	0