Éste es un breve resumen de la presentación dada en el Quinto Congreso de Química de América del Norte, celebrado en Cancún, Quintana Roo, México, en noviembre 1997. Se presentan varias alternativas posibles para la reducción de escala en experimentos de química inorgánica, y como ejemplo, un par de experimentos específicos con sus detalles prácticos.

This experiment describes the reaction of palladium(II) chloride with 1,5-bis(diphenylphosphino)pentane by grinding the two powders together in the solid state. The product is the precursor for the metalation reaction at one of the methylene carbon atoms of the ligand's backbone. The final product is known to be a catalyst for Suzuki−Miyaura coupling. Interesting NMR spectra combine with the example of a mechanical synthesis and a reflux under nitrogen to make this a useful upper-level undergraduate inorganic experiment.

A protocol that emphasizes lab report writing using a piecemeal approach coupled with peer review is described. As the lab course progresses, the focus of the report writing changes sequentially through the abstract and introduction, the discussion, and the procedure. Two styles of lab programs are presented. One style rotates the students through the experiments on a weekly basis, whereas the other style is a lockstep process but modified to divide the class in two. This protocol increases the quality of the writing experience without losing experimental content or increasing the students' workload.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of Formazan Dyes. Synthesis and Characterization of a Stable Verdazyl Radical and a Related Boron-Containing HeterocycleDavid E. Berry , Robin G. Hicks , and Joe B. Gilroy View Author Information Department of Chemistry, University of Victoria, Victoria, British Columbia, V8W 3V6, CanadaCite this: J. Chem. Educ. 2009, 86, 1, 76Publication Date (Web):January 1, 2009Publication History Received3 August 2009Published online1 January 2009Published inissue 1 January 2009https://pubs.acs.org/doi/10.1021/ed086p76https://doi.org/10.1021/ed086p76research-articleACS PublicationsRequest reuse permissionsArticle Views1516Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Crystal structure,Dyes and pigments,Electron paramagnetic resonance spectroscopy,Heterocyclic compounds,Students Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemical Synthesis and Ligand Exchange Reactions of Ru(CO)4(n2-alkene) CompoundsJason Cooke , David E. Berry , and Kelli L. Fawkes View Author Information Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada Department of Chemistry, University of Victoria, Victoria, BC V8W 3V6, CanadaCite this: J. Chem. Educ. 2007, 84, 1, 115Publication Date (Web):January 1, 2007Publication History Received3 August 2009Published online1 January 2007Published inissue 1 January 2007https://pubs.acs.org/doi/10.1021/ed084p115https://doi.org/10.1021/ed084p115research-articleACS PublicationsRequest reuse permissionsArticle Views491Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Alkyls,Hydrocarbons,Infrared spectroscopy,Irradiation,Organic compounds Get e-Alerts

This article describes two experiments suitable for a first-year general chemistry laboratory program emphasising “everyday chemistry.” The first experiment is the synthesis of various inorganic pigments that have been used by artists painting in oils. The second treats such pigments as unknown samples in a semimicroanalysis scheme, allowing the goal to be a detection of forgery. Each experiment can be performed in a three-hour time period and can be conveniently tailored for a team or individual exercise.

The teaching laboratory is an ideal environment for fostering active learning; yet, it is often criticized for being too “cookbook.” In introductory courses, the high student population often dictates that many students perform the same experiment simultaneously. By working in discussion groups, with individual bench work, we are able to turn this communal effort into a strength. This article describes the revision of a recipe-style experiment into a student-designed procedure.

This article describes two experiments suitable for a first-year general chemistry laboratory program emphasising “everyday chemistry.” The first experiment is the synthesis of various inorganic pigments that have been used by artists painting in oils. The second treats such pigments as unknown samples in a semimicroanalysis scheme, allowing the goal to be a detection of forgery. Each experiment can be performed in a three-hour time period and can be conveniently tailored for a team or individual exercise.

This article describes two experiments suitable for a first-year general chemistry laboratory program emphasising “everyday chemistry.” The first experiment is the synthesis of various inorganic pigments that have been used by artists painting in oils. The second treats such pigments as unknown samples in a semimicroanalysis scheme, allowing the goal to be a detection of forgery. Each experiment can be performed in a three-hour time period and can be conveniently tailored for a team or individual exercise.

A novel flavone-C-glycoside, aciculatin (1), has been isolated from the methylene chloride extract of Chrysopogon aciculatis (Poaceae) collected in the Philippines. The structure of 1 was determined by analysis of spectral data. Aciculatin exhibits cytotoxicity towards KB cells that is reduced by an order of magnitude in the presence of exogenous DNA indicating that 1 binds to DNA. DNA binding assays indicated an apparent Kd of 15 – 50 μM for binding of 1 to calf thymus DNA.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and phosphorus-31 NMR spectroscopy of trinuclear, phosphido-bridged iridium and rhodium clusters. Crystal and molecular structures of [M3(.mu.-PPh2)3(CO)nL2] (M = Ir or Rh, n = 3, L2 = 1,2-bis(diphenylphosphino)methane; M = Ir, n = 5, L = tert-BuNC)David E. Berry, Jane Browning, Khashayar Dehghan, Keith R. Dixon, Neil J. Meanwell, and Andrew J. PhillipsCite this: Inorg. Chem. 1991, 30, 3, 396–402Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February 1991https://pubs.acs.org/doi/10.1021/ic00003a009https://doi.org/10.1021/ic00003a009research-articleACS PublicationsRequest reuse permissionsArticle Views85Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Reaction of [Ir2(cyclooctene)4Cl2] with CO, NHEt2, and PHPh2 provides a synthetic route to the trinuclear, phosphido-bridged iridium clusters [Ir3(mu-PPh2)3(CO)nL2] (n = 3, L = CO or PPh3, L2 =bis(diphenylphosphino)methane (dppm); n = 5, L = t-BuNC). The CO andPPh3 complexes are analogues of previously known rhodium derivatives, and rhodium analogues of the dppm and t-BuNC complexes are also reported. [Ir3(mu-PPh2)3(CO)3(dppm)] (I) and [Rh3(mu-PPh2)3(CO)3(dppm)] (II) crystallize in the Pnma space group (Z = 4) with the following respective unit cell dimensions: a = 23.963 (5) angstrom, b = 24.970 (5) angstrom, c = 11.080 (2) angstrom; a = 24.031 (6) angstrom, b = 25.069 (9) angstrom, c = 11.117 (4) angstrom. [Ir3(mu-PPh2)3(CO)5(t-BuNC)2] (III) crystallizes in the P2(1)/n space group (Z = 4) with a = 23.015 (4) angstrom, b = 20.197 (6) angstrom, c = 11.849 (5) angstrom, and beta = 92.19 (4)degrees. The structures of I and II consist of approximately equilateral triangles of metal atoms (average M-M distances 2.78 (Ir) and 2.79 angstrom (Rh)), with the CO and two PPh2 ligands lying approximately in the M3 plane. The third PPh2 bridge is approximately perpendicular to this plane, linking the two basal metal atoms, which are also bridged by the dppm ligand. In contrast, the structure of III has all three PPh2 bridges approximately in the M3 plane with the t-BuNC ligands added approximately perpendicular to this plane at the apical iridium. The Ir-Ir distances are much longer, averaging 3.23 angstrom. Complete analyses of P-31 NMR spectra are reported for I-III and for IV, the Rh analogue of III. The phosphido bridge shifts reflect the changes in metal-metal distances, with I and II strongly deshielded (by 80-240 ppm) relative to III and IV. There is also a general reduction in the one-bond Rh-P coupling constants in the 50-electron cluster, IV relative to the 46-electron cluster, II.

Reactions of the bisphosphine monochalcogenides, [Ph 2 PCH 2 P(Y)R 2 ], Y = O, S, or Se, R = Ph, Pr i , or Bu t , with the chloro-bridged dimers [M 2 Cl 4 (PR′ 3 ) 2 ], M = Pd or Pt, R′ = Et or Bu n , in the presence of either NaClO 4 or NaBF 4 yield perchlorate and fluoroborate salts of the complex cations cis- and trans-[PtCl(PR′ 3 ){Ph 2 PCH 2 P(Y)R 2 }] + . In many cases both cis and trans isomers (defined by the relative orientation of the two M—P bonds) are obtained and the precise isomer distribution is a sensitive function of the substituents. Corresponding neutral complexes, cis- and trans-[PtCl(PR′ 3 ){Ph 2 PCHP(Y)R 2 }], can be synthesized either by deprotonation of the cations using NaH or by use of the salts Li[Ph 2 PCHP(Y)R 2 ] in the initial bridge cleavage reactions. These and related complexes are characterized by complete 13 C, 31 P, 77 Se, and 195 Pt NMR studies and by two crystal structure determinations. The complexes I, trans-[PtCl(PEt 3 ){Bu t 2 PCH 2 P(O)Me 2 }][ClO 4 ], and II, trans-[PtCl(PEt 3 ){Ph 2 PCH 2 P(S)Bu t 2 }][ClO 4 ], crystallize in the monoclinic space group P2 1 /c, respective cell dimensions: a = 15.579(2), b = 13.590(3), c = 13.578(1) Å;β= 105.96(1)°; and a = 14.002(4), b = 16.366(5), c = 15.524(5) Å; β = 106.01 (3)°. Complete X-ray diffraction studies show that both complexes contain closely square planar platinum centres with the R 2 PCH 2 P(Y)R′ 2 ligands coordinated via phosphorus and the Y atom so as to form five-membered chelate rings. The molecular dimensions suggest that the bond to sulphur is stronger than that to oxygen and exerts a larger trans influence.