Thompson Izuagie - Academia.edu (original) (raw)

Uploads

Papers by Thompson Izuagie

Caliphate Journal of Science and Technology, Aug 10, 2022

Non-aqueous methodologies provide an opportunity to access a range of polyoxometalates that may n... more Non-aqueous methodologies provide an opportunity to access a range of polyoxometalates that may not be stable in H2O and enable mechanistic studies into hydrolytic and protonation behaviours, which are fundamental to polyoxometalate chemistry. 17 O-enriched (TBA)6[NaPW11O39] was prepared via an efficient non-aqueous route and shown to be a suitable precursor to [(L)MPW11O39] n-(M = Sn 2+ , Pb 2+ , Bi 3+ , Sb 3+ , Sn 4+ , Ti 4+) for detailed systematic studies. Reactions were monitored by 31 P NMR while products were characterised by FT-IR, multinuclear NMR (1 H, 13 C, 17 O, 31 P, 119 Sn, 183 W and 207 Pb), solid state NMR, ESI-MS, CHN microanalysis, UV-Vis and/or single crystal XRD. Using this approach, the readily-hydrolysable tin derivatives, (TBA)4[(CH3O)SnPW11O39] and (TBA)8[(µ-O)(SnPW11O39)2] were prepared for the first time and the previously reported (TBA)4[(HO)TiPW11O39] was shown to be stable in DMSO for up to 3 months possibly due to interaction between HO-and DMSO. As a result of the more ionic character of Sn-OCH3 bond compared with Ti-OCH3, (TBA)4[(CH3O)SnPW11O39] was observed to hydrolyse faster than (TBA)4[(CH3O)TiPW11O39] whereas (TBA)4[ClTiPW11O39] with a large excess of H2O hydrolysed more readily than (TBA)4[ClSnPW11O39]. Although (TBA)4[(HO)TiPW11O39] underwent condensation to (TBA)8[(µ-O)(TiPW11O39)2] easily in acetonitrile at room temperature, this reaction only occured for (TBA)4[(HO)SnPW11O39] at elevated temperature (~120 o C) in the presence of a waterscavenging agent such as N, N'-dicyclohexylcarbodiimide (DCC). These experimental observations were consistent with DFT calculations on the energetics of the hydrolysis and condensation of (TBA)4[(CH3O)SnPW11O39] and (TBA)4[(CH3O)TiPW11O39]. Protonation studies on the 17 O-enriched POMs provided insights into protonation of the MOW sites in (TBA)4[(CH3O)TiPW11O39], (TBA)4[ClM IV PW11O39] (M = Sn, Ti), (TBA)5[M II PW11O39] (M = Sn, Pb) and (TBA)4[M III PW11O39] (M = Sb, Bi) and protonation at both TiOW and TiOTi sites in (TBA)8[(µ-O)(TiPW11O39)2] whilst reactions between (TBA)8[(µ-O)(TiPW11O39)2] and electrophiles indicated possible formation of adducts. Treatment of (TBA)4[(L)SnPW11O39] (L = Cl, HO) with NaBH4 resulted in reduction of the tin heteroatom only whereas reaction between (TBA)5[Sn II PW11O39] and halogens (Br2 and I2) or the molybdate (TBA)3[PMo12O40] showed oxidation of tin (II). Electrochemical studies in acetonitrile revealed no redox processes associated with the heterometals in (TBA)4[(L)Sn IV PW11O39] and (TBA)5[Pb II PW11O39] while redox waves assigned to Sn 2+ /Sn 4+ were observed for Abstract ii (TBA)5[Sn II PW11O39] within the potential range studied. Finally, attempts to prepare Lindqvist-type derivatives, [(L)MW5O18] n-(

Structure and Bonding, 2017

Abstract-The aim of this study was to compare the compaction property of starch extracted from se... more Abstract-The aim of this study was to compare the compaction property of starch extracted from seeds of Christ Thorn with that of standard commercial corn starch. Starch from Christ thorn seeds was extracted by hot water method whereas standard commercial corn starch ...

Bayero Journal of Pure and Applied Sciences, Sep 7, 2012

Starch was extracted from seeds of Christ Thorn by hot water extraction method. The composition a... more Starch was extracted from seeds of Christ Thorn by hot water extraction method. The composition and physicochemical properties of the extracted starch were determined using standard methods. The results obtained from the analyses revealed that the % yield of starch was 43.2%, while moisture content, ash content, starch protein and starch lipid were 7.8%, 0.01%, 0.12% and 0.32% respectively. The results also showed amylose content of 24.6%; swelling power of 37.5g/g, solubility of 2.1%, amylose leaching of 3.7% and gelatinization temperature of 68 o C. From the results, the paper concludes that with minor modifications, the seeds can be used as alternative sources of starch for industrial products.

International Journal of Science for Global Sustainability

The paper examines the efficiency of nanoporous carbon modified with copper nanoparticles (nC@CuN... more The paper examines the efficiency of nanoporous carbon modified with copper nanoparticles (nC@CuNPs) for the removal of microbial contaminants from polluted waters. The modified material was prepared by wet impregnation of the unmodified carbon material in a solution of as-prepared Cu-nanoparticles. The materials were characterized by UV-Visible Spectroscopy, Fourier Transform-Infrared (FTIR) Spectroscopy, and Thermogravimetric Analysis. The materials were then investigated for their ability to remove copper and lead using Atomic Absorption Spectroscopy (AAS), methylene blue using Ultraviolet-Visible (UV-Vis) Spectroscopy and microbial contaminants from simulated polluted water. The results showed that in addition to retaining its heavy metals (Cu and Pb), and methylene blue removal capacity, the modified material, nC@CuNPs was efficient in removing microbial contaminants (E. coli and Salmonella) from the polluted water. The study provides an avenue for the provision of easy access ...

Caliphate Journal of Science and Technology

Access to clean water by all is one of the UN Sustainable Development Goals. To achieve this, the... more Access to clean water by all is one of the UN Sustainable Development Goals. To achieve this, there is need to prepare sustainable materials for efficient water purification. This research aims to immobilize the Polyoxomatelate-Ionic Liquid (POM-IL), {[CH3(CH2)6]4N}7[α-PW11O39] on nanoporous carbon (NC) prepared from coconut shell to form an advanced material (POM-IL@NC) for effective removal of multiple contaminants from polluted water. The POM-IL@NC material was characterized by Fourier Transform-Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) Analysis and Brunauer-Emmett-Teller (BET) method. The material was then tested respectively for the removal of copper and lead using Atomic Absorption Spectroscopy (AAS) and methylene blue using Ultraviolet-Visible (UV-Vis) Spectroscopy from simulated polluted waters via adsorption. The material was further subjected to antimicrobial analysis. The results showed that the POM-IL@NC material performed ...

International Journal Of Science for Global Sustainability, Dec 30, 2015

Polyoxometalate-Based Assemblies and Functional Materials, 2017

This paper examines the physicochemical properties of starch extracted from seeds of Faidherbia a... more This paper examines the physicochemical properties of starch extracted from seeds of Faidherbia albida collected form different locations within Sokoto metropolis. After extraction by hot water method, the starch was subjected to physicochemical analysis. The results of the analysis showed that the starch yield was 39.2% while the starch pH was 7.2. Also, the moisture content, ash content, starch protein, starch lipid, and amylose content of the starch were 7.3%, 0.02%, 0.72%, 0.27% and 26.7% respectively. Equally, the results showed that the swelling power, solubility and extent of amylose leaching were 10.7g/g, 2.9% and 5.9% respectively. Thus, the study concludes that F. albida starch may

IOSR Journal of Applied Chemistry, 2013

Starch is widely used in the food and pharmaceutical industries for various applications. These i... more Starch is widely used in the food and pharmaceutical industries for various applications. These industries often rely on crops that are also traditional sources of food by man resulting high demand with consequence economic implications. In this work starches from four varieties of mango (Mangifera indica) seeds were extracted and characterised using standard methods for potential industrial applications. The results showed that the average starch content of the seeds is 60.44±5.26% although there are statistically significant differences amongst the varieties. Moisture content (6.23±1.36%), ash content (0.158±0.101%), starch protein (0.0669±0.0027%) and starch lipid (0.208±0.0417 %,) were low. Amylose content was within the range of 11.90-16.74%. Swelling power (19.40±0.30-19.80±0.36g/g) and solubility (0.135±0.002-0.142±0.001%) were less variable amongst the varieties. The Amylopectin content of the starches was within the range of 83.25±0.10-90.60±0.40%); and significant variations (p<0.05) were observed amongst the mango varieties. It was also observed that the onset gelatinization temperature of the starches ranged from 60.5 to 63.4 o C whereas the conclusion gelatinization temperature was from 70.2 to 73.4 o C. In general, even though there are significant differences in some of the properties of the starches, the starches show good properties and could serve as alternatives for the production of industrial products that may require starch.

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.