50 research outputs found
Workshops redeveloped: Group work to nurture a more inclusive learning environment
Merging assessment and feedback during continuous assessment involves the seamless integration of evaluating learning outcomes with providing constructive feedback to enhance learning. An illustrative example of this integration can be observed in active-learning-based analytical chemistry workshops conducted for a core undergraduate module within a chemistry programme. Extensive inquiring with students indicates that combining group work and merging assessment and feedback in these workshops can yield a multitude of benefits, including increased efficiency and enhanced communication, subsequently leading to a more inclusive learning environment.
This article was published open access under a CC BY licence:
https://creativecommons.org/licences/by/4.0
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Evaluation of lab performance: An assessment of progress or a record of failures?
With the increasing recognition of the importance of good academic practices, various disciplines are striving to enhance their assessment strategies to foster inclusivity. The conventional evaluation of laboratory performance requires immediate adjustments to tackle issues such as subjective grading, inconsistent marking, and a lack of student engagement. In line with our research project on re-designing assessment in chemistry education, we have undertaken the task of revamping the assessment strategy for several chemistry modules aimed at intermediate years of undergraduate study at the University of Liverpool. Specifically, we have focused on implementing alternative more inclusive forms of continuous assessment of lab practice. This paper presents the results of implementing these assessment changes and incorporates initial student evaluations to provide valuable insights into their effectiveness.
This article was published open access under a CC BY licence:
https://creativecommons.org/licences/by/4.0
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Substrate-Selective C-H Functionalization for the Preparation of Organosulfur Compounds from Crude Oil-Derived Components
The
direct utilization of a natural feedstock in organic synthesis
is an utmost challenge because the selective production of one product
from a mixture of starting materials requires unprecedented substrate
selectivity. In the present study, a simple and convenient procedure
is evaluated for the substrate-selective alkenylation of a single
component in a mixture of organosulfur compounds. Pd-catalyzed alkenylation
of two-, three-, four-, and five-component mixtures of crude oil-derived
sulfur species led to the exclusive C–H functionalization of
only one compound. The observed remarkable substrate selectivity opens
new opportunities for sustainable organic synthesis
Pd-II-mediated integration of isocyanides and azide ions might proceed via formal 1,3-dipolar cycloaddition between RNC ligands and uncomplexed azide
The generation of (tetrazolate)PdII complexes via the integration of (isocyanide)PdII precursors with uncomplexed azides and the verification of plausible reaction mechanisms.</p
A novel samarium(II) complex bearing a dianionic bis(phenolate) cyclam ligand: synthesis, structure and electron-transfer reactions
A novel divalent samarium complex anchored on a dianionic bis(phenolate) ligand is reported and reactivity studies demonstrate that it is highly effective in inducing single-electron transfer processes.</p
Phosphorescent Cyclometalated Palladium(II) and Platinum(II) Complexes Derived from Diaminocarbene Precursors.
Metal-mediated self-assembly of isocyanides and methyl 4-aminopyrimidine-5-carboxylate leads to luminescent PdII and PtII complexes featuring C,N-cyclometalated acyclic diaminocarbene (ADC) ligands. The solid-state luminescent properties of these diaminocarbene derivatives are attributed to their triplet-state metal/metal-to-ligand charge-transfer (3MMLCT) nature, which is driven by attractive intermolecular M···M interactions further reinforced by the intramolecular π-π interactions even in the structure of the Pd compound, which is the first Pd-ADC phosphor reported
Palladium(II)-Mediated Addition of Benzenediamines to Isocyanides: Generation of Three Types of Diaminocarbene Ligands Depending on the Isomeric Structure of the Nucleophile
Coupling
of the palladium-bis(isocyanide) complexes <i>cis</i>-[PdCl<sub>2</sub>(CNR)<sub>2</sub>] (R = 2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub> <b>1</b>, 2-Cl-6-MeC<sub>6</sub>H<sub>3</sub> <b>2</b>) with benzene-1,3-diamine (<b>BDA1</b>) leads to the
diaminocarbene species <i>cis</i>-[PdCl<sub>2</sub>(CNR){C(NHR)NH(1,3-C<sub>6</sub>H<sub>4</sub>NH<sub>2</sub>)}] (<b>5</b> and <b>6</b>, respectively). In this reaction, <b>BDA1</b> behaves as a
monofunctional nucleophile that adds to one of the RNC ligands by
one amino group. By contrast, the reaction of <b>1</b> and <b>2</b> with benzene-1,4-diamine (<b>BDA2</b>) involves both
amino functionalities of the diamine and leads to the binuclear species
[<i>cis</i>-PdCl<sub>2</sub>(CNR){μ-<u>C</u>(NHR)NH(1,4-C<sub>6</sub>H<sub>4</sub>)NH<u>C</u>(NHR)}<i>-</i>(<i>cis</i>)-PdCl<sub>2</sub>(CNR)] (<b>6</b> and <b>7</b>) featuring two 1,4-bifunctional
diaminocarbene ligands. The reaction of <i>cis</i>-[PdCl<sub>2</sub>(CNR)<sub>2</sub>] (R = cyclohexyl <b>3</b>) with either <b>BDA1</b> or <b>BDA2</b> does not afford any isolable carbene
derivatives. The most versatile chemistry was observed when <b>1</b>–<b>3</b> were treated with benzene-1,2-diamine
(<b>BDA3</b>) and the relevant substituted 1,2-diamines, viz.,
4,5-dimethylbenzene-1,2-diamine (<b>BDA4</b>) and 4,5-dichlorobenzene-1,2-diamine
(<b>BDA5</b>). The addition of these diamines brings about the
formation of the monocarbene cationic complexes <i>cis</i>-[PdCl(CNR){<u>C</u>(NHR)NHC<sub>6</sub>H<sub>2</sub>X<sub>2</sub><u>N</u>H<sub>2</sub>}]Cl (X
= H, Me, Cl) (<b>8</b>–<b>16</b>), the Chugaev-type <i>C,C</i>-bound bis-carbenes <i>cis</i>-[PdCl<sub>2</sub>{<u>C</u>(NHR)NHC<sub>6</sub>H<sub>2</sub>X<sub>2</sub>NH<u>C</u>(NHR)}] (<b>17</b>, <b>18</b>), and the bis(<i>C,N</i>-chelated)carbene
complexes <i>cis</i>-[Pd{<u>C</u>(NHR)NHC<sub>6</sub>H<sub>2</sub>X<sub>2</sub><u>N</u>H<sub>2</sub>}<sub>2</sub>]Cl<sub>2</sub> (<b>19</b>–<b>24</b>). All prepared complexes (with the exception of <b>17</b> and <b>18</b>) were isolated as colorless or pale yellow solids and characterized
by elemental analyses (C, H, N), HRESI<sup>±</sup>-MS, IR, <sup>1</sup>H and <sup>13</sup>C{<sup>1</sup>H} NMR spectroscopies, and <b>4</b>, <b>7</b>, <b>13</b>, <b>16</b>, and <b>24</b> by X-ray diffraction. Complexes <b>17</b> and <b>18</b> were characterized by HRESI<sup>±</sup>-MS and IR
spectroscopy, and their structures were established by X-ray crystallography
Open-book examination in analytical chemistry: A valuable approach that promotes inclusivity in education, as seen by students
An open-book examination is a valuable approach that promotes inclusivity in education by placing greater emphasis on critical thinking, analysis, and the practical application of knowledge, rather than mere rote memorization. It enables students to consult the course materials, textbooks, and additional resources during the exam, thus creating an equitable platform for all learners. This brief communication delves into the students’ perception of open-book examinations within the realm of analytical chemistry, a subject taught as part of the undergraduate chemistry programme. Both surveys and individual interviews conducted by the researchers were used in a complementary way as methods for data collection. Thematic and content analysis of surveys and interview outcomes were subsequently undertaken. By exploring the viewpoints, we gained valuable insights into the advantages and challenges associated with implementing open-book assessments in this specific field.
This article was published open access under a CC BY licence:
https://creativecommons.org/licences/by/4.0
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</jats:p
Reactivity of bulky tris(Phenylpyrazolyl) methanesulfonate copper(I) complexes towards small unsaturated molecules
Reaction of the tris(3-phenylpyrazolyl)methane sulfonate species (Tpms(Ph))Li with the copper(I) complex [Cu(MeCN)(4)][PF6] affords [Cu(Tpms(Ph))(MeCN)] 1. The latter, upon reaction with equimolar amounts of cyclohexyl-(CyNC) or 2,6-dimethylphenyl (XylNC) isocyanides, or excess CO, furnishes the corresponding Cu(I)complexes [Cu(Tpms(Ph))(CNR)] (R = Cy 2, Xyl 3) or [Cu(Tpms(Ph))(CO)] 4. The ligated isocyanide in 2 or 3 (or the acetonitrile ligand in 1)is displaced by 3-iminoisoindolin-1-one to afford 5, the first copper(I) complex containing an 3-iminoisoindolin-1-one ligand. The ligated acetonitrile in 1 undergoes nucleophilic attack by methylamine to give the amidine complex [Cu(Tpms(Ph)){MeC(NH)NHMe}] 6, whereas only the starting materials were recovered from the attempted corresponding reactions of 2 and 3 with methylamine. Complexes 1 or 6 form the trinuclear hydroxo-copper(II)species [(mu-Cu){Cu(mu-OH) (2)(Tpms(Ph))}(2)] 7 upon air oxidation in moist methanol. In all the complexes the scorpionate ligand facially caps the metal in the N,N,O-coordination mode