Research and Development

@article{Reyes2021,

title = {Facile Grignard Reaction Demonstration Using Molecular Sieved Dried Solvent},

author = {Jude M. Reyes and John Vincent M. Tumaneng and Gilbert U. Yu},

doi = {10.1021/acs.chas.1c00015},

issn = {1878-0504},

year  = {2022},

date = {2022-01-24},

journal = {ACS Chem. Health Saf.},

volume = {29},

number = {1},

pages = {49--53},

publisher = {American Chemical Society (ACS)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Perez2017,

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},

author = {Angelo Julian E. Perez and Armando M. Guidote Jr. and Gilbert U. Yu and Michael Ner E. Mariano},

url = {https://kimika.pfcs.org.ph/index.php/kimika/article/view/219},

doi = {10.26534/kimika.v27i2.50-62},

issn = {2508-0911},

year  = {2017},

date = {2017-02-08},

journal = {KIMIKA},

volume = {27},

number = {2},

pages = {50-62},

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.},

keywords = {chemistry education, general chemistry, history and philosophy of science, nature of science, philosophy of chemistry, textbook analysis},

pubstate = {published},

tppubtype = {article}

}

@article{Yu2016,

title = {Cationic and Neutral Rotaxanes Having Different Functional Groups in the Axle Molecule and Their Coordination to PtII},

author = {Gilbert U. Yu and Yuji Suzaki and Kohtaro Osakada},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/asia.201601554},

doi = {10.1002/asia.201601554},

year  = {2016},

date = {2016-12-14},

journal = {Chemistry - An Asian Journal},

volume = {12},

number = {3},

pages = {372-377},

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 1H 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.},

keywords = {“click” reaction, macrocycle shuttling, platinum complex, rotaxanes, triazole ligand},

pubstate = {published},

tppubtype = {article}

}

@article{Yu2016b,

title = {Ferrocene-containing [1]-, [2]-, [3]- and [4]rotaxanes synthesized from a common precursor},

author = {Gilbert U. Yu and Yuji Suzaki and Kohtaro Osakada},

url = {https://pubs.rsc.org/en/content/articlelanding/2016/RA/C6RA05688A},

doi = {10.1039/C6RA05688A},

year  = {2016},

date = {2016-04-26},

journal = {RSC Advances},

volume = {6},

number = {27},

pages = {41369-41375},

abstract = {The Cu-catalyzed reaction of a dialkylammonium, having ferrocenyl and hexynyl end groups, FcCH2NH2CH2C6H4–4-O(CH2)4C[triple bond, length as m-dash]CH]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)4C[triple bond, length as m-dash]CH]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.},

keywords = {-},

pubstate = {published},

tppubtype = {article}

}

@article{Yu2011,

title = {Opacity of P(MMA-MAA)-PMMA Composite Latex Systems with Varying MAA Concentration},

author = {Gilbert U. Yu and Jerry T. Dy and Erwin P. Enriquez},

url = {https://philjournalsci.dost.gov.ph/home-1/34-vol-140-no-2-december-2011/452-opacity-of-p-mma-maa-pmma-composite-latex-system-with-varying-maa-concentration},

issn = {0031-7683},

year  = {2011},

date = {2011-12-01},

journal = {Philippine Journal of Science},

volume = {140},

number = {2},

pages = {221-230},

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.},

keywords = {core-shell, emulsion polymerization, latex morphology, opacity},

pubstate = {published},

tppubtype = {article}

}