Sex: Male
Education:
- Doctor of Engineering, Tokyo Institute of Technology, Japan, 2012
- Master of Science in Chemistry, McMaster University, Canada, 2008
- Master of Science in Chemistry, Ateneo de Manila University, Philippines, 2005
- B.S. in Management of Applied Chemistry, Ateneo de Manila University, Philippines, 1999
Field of Specialization:
General Chemistry
Organic Chemistry
Analytical Chemistry
Instrumentation Chemistry
Physical Chemistry
Researches:
Article title: Facile Grignard Reaction Demonstration Using Molecular Sieved Dried Solvent
Authors: Jude M. Reyes, John Vincent M. Tumaneng, and Gilbert U. Yu
Publication title: ACS Chemical Health and Safety 29(1): 49-53, 2022
Abstract:
Methods involving C–C bond formation are continuously being innovated due to their importance in the creation and modification of important organic molecules. The classic Grignard reaction demonstrates C–C bond formation with reagents that are usually accessible in undergraduate laboratory classes. Oftentimes, to make the Grignard reaction viable, the reactions are assisted by heating at elevated temperatures or with the use of a catalyst accompanied by solvents that have been dried using highly reactive sodium metal (Na0)─conditions which increase the risk of a laboratory fire or explosion. For this work, a method to conduct Grignard reactions under mild conditions utilizing sand-paper-polished Mg ribbons and solvent dried using molecular sieves was developed. The conscientious, accessible, and easy-to-follow preparation of both the solvent and the Mg ribbons is found to contribute more to the percent conversion of reagents to products. The average percent conversion with the proposed method ranged from 76.8% to 99.5% based on 1H NMR results. This makes the Grignard demonstration possible even for the most humid, tropical locations.
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Article title: Formulating 3-Chloropropyltriethoxysilane Modified Silica Nanoparticle Sprays as Hydrophobic Transparent Coatings onto Cotton Textiles
Authors: Mikaela C.S. Mendoza and Gilbert U. Yu
Publication title: Philippine Journal of Science 150(3): 1069-1076
Abstract:
Cotton textiles were transformed into hydrophobic fabrics via the application of 3-chloropropylthriethoxysilane-functionalized silica nanoparticle spray coatings. Silica particles were measured to be < 50 nm, as determined by dynamic light scattering (DLS). The incorporation of hexadecyltrimethylammonium bromide (HTAB), a surfactant, into the nanosilica alcohol-based sprays resulted in a suspension that was stable for at least a week. Stability and turbidity tests of samples point to smaller particle size (silica nanoparticles = 24.3 ± 8.5 nm) as the main contributor to possibly providing transparency, as evidenced when sprayed in colored (black) textiles, while still contributing to hydrophobicity/ superhydrophobicity of the cloth.
Full text link https://tinyurl.com/3xf4wnmw
Article title: Cationic and Neutral Rotaxanes Having Different Functional Groups in the Axle Molecule and Their Coordination to Pt(II),
Authors: Gilbert Yu, Yuji Suzaki, Kohtaro Osakada
Publication title: Chemistry: Asian journal 12(3):372-377, 2017
Abstract:
Dibenzo[24]crown-8 (DB24C8) forms rotaxanes with a linear molecule having a dialkylammonium group and a triazole group as well as with the acetylation product of a cationic axle molecule. The former cationic rotaxane is stabilized by multiple intermolecular hydrogen bonds between the NH2+ and oxyethylene groups. The neutral rotaxane contains the macrocycle in the vicinity of the terminal aryl group. The co-conformation of both the cationic and neutral rotaxanes can be fixed by coordination of the triazole group of the axle molecule to PtCl2 (dmso)2 . A 1 H NMR spectroscopic study on the thermodynamics of the Pt coordination revealed a larger association constant for the rotaxanes than for the corresponding axle molecules and a larger value for the neutral rotaxane than for the cationic rotaxane.
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Article title: Ferrocene-containing [1]-, [2]-, [3]-and [4]rotaxanes Synthesized From a Common Precursor
Authors: Gilbert Yu, Yuji Suzakia and Kohtaro Osakada
Publication title: RSC Advances 6:41369-41375, 2016
Abstract:
The Cu-catalyzed reaction of a dialkylammonium, having ferrocenyl and hexynyl end groups, FcCH2NH2CH2C6H4–4-O(CH2)4CCH]PF6 (Fc = Fe(C5H4)(C5H5)), with a crown ether having an azidemethyl side-arm yields a [1]rotaxane composed of a single molecule. The crystal structure of the [1]rotaxane suggests an arrangement where the 1,4-phenylene ring is tilted at 22° close to the catechol ring rather than in a parallel alignment. Another dialkylammonium with ferrocenyl and alkynyl terminal groups, [FcCH2NH2CH2C6H4–4-O(CH2)4CCH]PF6, reacts with aromatic compounds with one to three azide groups in the presence of dibenzo[24]crown-8-ether (DB24C8) and [Cu(MeCN)4]PF6 catalyst, to afford the corresponding [2]–[4]rotaxanes. The products contain DB24C8 molecules as the cyclic components which are bound to the ammonium group of the axle component with NH⋯O hydrogen bonding. The [3]rotaxane having two triazole groups on the axle component reacts with PdCl2(MeCN)2 to yield mono- and di-palladium complexes with different conformations of the axle component.
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Article title: Content Analysis of the Discussion of the Atom in General Chemistry Textbooks Using Evaluation Criteria Based on the Nature of Science and Philosophy of Chemistry
Authors: Angelo Julian E. Perez, Armando, Jr. M. Guidote, Gilbert U. Yu, Michael Ner E. Mariano
Publication title: Kimika 27(2): 50-62, 2016
Abstract:
Evaluation criteria are adapted from previous textbook analyses on the nature of science (NOS) in general chemistry textbooks. These criteria are used to determine how certain NOS dimensions are mentioned and elaborated in those textbooks. Such dimensions emphasize that chemistry is (1) tentative, (2) empirical, (3) model-based, (4) inferential, (5) has technological products, (6) employs instrumentation, and (7) possesses social and societal dimensions. Three book chapters were read and evaluated: the first (on chemistry in general); the second (on atomic structure); and the sixth or seventh chapters (on the electronic structure of atoms). The relevant content in each textbook were rated using the following rubric: Satisfactory and Explicit (S, 2 points); Mention and Implicit (M, 1 point); and No Mention (N, 0 point). Silberberg (2009) has the highest score among the six textbooks with 12 points out of the maximum of 14. It was rated S for five criteria, the most among the six textbooks. Despite the presence of some N evaluations, all textbooks have mentioned some or all of the NOS dimensions formulated, resulting to M and S ratings. This study concludes that NOS dimensions are already present in various ways and varying degrees in each textbook.
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Article title: Silica Nanospheres Functionalized by Ferrocene-containing [2]Rotaxane,
Authors: Gilbert Yu, Yuji Suzaki, Yujin Maekawa, Tomoko Abe, Kohtaro Osakada, Toshiyuki Yokoi
Publication title: Chemistry Letters 43(6): 953-955, 2014
Abstract:
Rotaxane having ferrocenyl group at a terminal of the axle molecule was immobilized to the surface of silica nanospheres by condensation of the triethoxysilyl terminal group with OH groups of the silica.
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Article title: Introduction of Ferrocene-containing [2]Rotaxanes onto Siloxane, Silsesquioxane and Polysiloxanes via Click Chemistry
Authors: Gilbert Yu, Yuji Suzaki, Tomoko Abea and Kohtaro Osakada
Publication title: Dalton Transactions 42: 1476-1482, 2013
Abstract:
The reaction of N3(CH2)3Si(OTMS)3 (TMS = SiMe3) with a dialkylammonium having hexynyl group 1, [FcCH2NH2CH2C6H4-4-O(CH2)4C[triple bond, length as m-dash]CH]PF6 (Fc = Fe(C5H4)(C5H5)), in the presence of dibenzo[24]crown-8-ether (DB24C8) and [Cu{Fe(CN)4}]PF6 catalyst yielded the [2]rotaxane containing the dialkylammonium unit terminated by a bulky silyl group. Azides with a silsesquioxane group react similarly to form the corresponding [2]rotaxanes having a bulky silsesquioxane end group. The azide-functionalized polysiloxane, [–O–SiMe{(CH2)3N3}–]n[–O–SiMe2–]m also undergoes a click reaction with 1 to produce the side chain polyrotaxane. Cyclic voltammograms of these rotaxanes and 1 [(DB24C8)1] show the Fe(II)/Fe(III) redox at the same potential, but with different current depending on their molecular weights. Addition of PdCl2(MeCN)2 to a solution of the side-chain polyrotaxane forms gel which regenerates the sol upon addition of PPh3.
Full text available upon request to the author
Article title: Organometallic Rotaxanes with a Triazole Group in the Axle Component and Their Behavior as Ligands of Pt(II) Complexes;
Authors: Gilbert Yu, Yuji Suzaki, Tomoko Abe, Kohtaro Osakada
Publication title: Chemistry: an Asian Journal 7(1):207-13, 2012
Abstract:
Two ferrocenylmethyl ammonium salts were used as axle components of pseudorotaxanes with dibenzo[24]crown-8. The pseudorotaxane with an alkyne terminal group in the axle component underwent a Cu-catalyzed Huisgen coupling reaction (click reaction) with an alkyl azide to afford cationic [2]rotaxanes with a triazole group in the axle molecule. The rotaxane reacted with Ac(2) O to produce neutral rotaxanes with an amide group in the axle component. Both cationic and neutral rotaxanes were treated with K[PtCl(3)(CH(2)=CH(2))] to form the Pt(II)-containing rotaxanes.
Full text available upon request to the author
Article title: Opacity of P(MMA-MAA)-PMMA Composite Latex System with Varying MAA Concentration
Authors: Gilbert U. Yu, Jerry T. Dy, and Erwin P. Enriquez
Publication title: Philippine Journal of Science 140:221-230, 2011
Abstract:
Polymer composites of core-shell morphology are commonly used in the paint industry as opacity enhancer. These are usually made of block copolymer systems wherein the core is formed from a polymer that swells in the presence of a solvent and surrounded by a high glass transition polymeric shell. Thus, upon drying, the swollen regions turn into voids while leaving a hard shell. Here, composites based on poly(methyl methacrylate-butyl acrylate) [P(MMA-BuA)] (seed stage), poly(methyl methacrylate-methacrylic acid) [P(MMA-MAA)] (second stage), and poly(methyl methacrylate) [PMMA] (third stage) were synthesized through a multistage sequential emulsion polymerization and their opacity was investigated. The second stage formulation of P(MMA-MAA) system was varied by changing the methyl methacrylate (MMA): methacrylic acid (MAA) mole composition, and the dried films of these composite latexes were characterized by infrared spectroscopy (IR), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). The AFM images and ammonium hydroxide (NH4OH) swelling studies confirmed the successful incorporation of the seed (first) stage with the second and third stage polymerization with PMMA. The differences in PMAA concentrations among the second stage polymer compositions were determined from the IR spectra and glass transition temperature (Tg) data. Investigations on the opacity and hiding power of these polymer composites were done using optical densitometry. The results show increasing absorbance, indicating increasing opacity, with increasing polymethacrylic acid (PMAA) concentration in the second stage composition.
Full text link https://tinyurl.com/4688tjp7
Article title: Versatile, Efficient Derivatization of Polysiloxanes via Click Technology
Authors: Ferdinand Gonzaga, Gilbert Yua and Michael A. Brook
Publication title: Chemical Communications 1730-1732, 2009
Abstract:
Copper-catalyzed (click chemistry) or thermal 1,3-dipolar cycloadditions of molecular or polymeric azido-siloxanes with a broad range of alkynes (such as amino acids or carbohydrates) easily yield new conjugates that would be otherwise difficult, if not impossible, to prepare by traditional methodologies.
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Article title: Polysiloxane Elastomers via Room Temperature, Metal-Free Click Chemistry
Authors: Ferdinand Gonzaga, Gilbert Yu, and Michael A. Brook
Publication title: Macromolecules 42:9220-9224, 2009
Abstract:
No available
Full text link https://tinyurl.com/5djz4wv3
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