Plinio Sosa

RuX = C (X F or H) interactions in complex compounds. Preparation and crystal structures of [RuSC6F4(F-2) (SC6F5)2(PMe2Ph)2] and [Ru(SC6F5)2PC6H4(H-2)(C6H5)22]

The diamagnetic complex [Ru(SR)2(PPh3)2] and the paramagnetic compounds [Ru(SR)3(PR′3)2] (R = C6F5, C6F4H, C6FH4, or C6H5; PR′3 = PPh3, PMe2Ph or PEt2Ph) have been prepared by treatment of [RuCl2(PPh3)3] or [RuCl3(PR′3)3]. respectively, with [Pb(SR)2] in acetone or tetrahydrofuran. An X-ray diFfraction study on [Ru(SC6F5)2PC6H4(H-2)(C6H5)22] has revealed a pseudo-octahedral structure, apparently with two CHRu interactions. The complexes [Ru(SR)3(PR′3)2] have μeff in the range 1.8–1.9 BM and EPR spectra are reported. An X-ray study of [RuSC6F4(F-2)(SC6F5)2(PMe2Ph)2] has shown that it has essentially octahedral geometry, involving a CFRu interaction.

A C–F–Ru interaction in a complex: preparation and X-ray structure of [Ru{SC6F4(F-2)}(SC6F5)2(PMe2Ph)2]

Treatment of [RuCl3(PMe2Ph)2] with Pb(SC6F5)2 in acetone gives [[graphic omitted]-2)}(SC6F5)2(PMe2Ph)2] whose X-ray structure shows a C–F–Ru interaction.

PREPARATION AND ELECTROCHEMISTRY OF THIOLATE-PHOSPHINE COMPLEXES OF OSMIUM

Abstract —The paramagnetic, octrahedral complexes [Os(SC 6 F 5 ) 2 (O 2 CR)(PMe 2 Ph) 2 ] (R = C 6 F 5 , 1; C 6 H 4 CF 3 -2, 2; C 6 H 4 CF 3 -3, 3; C 6 H 4 CF 3 -4, 4; C 6 H 4 F-2, 5; C 6 H 4 F-3, 6; C 6 H 4 F-4, 7 ; CH 3 , 8 ; CF 3 , 9) have been prepared by treatment of the penta-coordinated complex [Os(SC 6 F 5 ) 3 (PMe 2 Ph) 2 ] with the corresponding fluoro-carboxylic acid. The diamagnetic, pentacoordinate, osmium(IV) complexes [OsX(SR) 3 (PR 3 1 )] [X = Cl, Br or SR; R = C 6 F 4 H-4 or C 6 F 5 ; PR 3 1 = PMe 2 Ph, PPh 3 , P(C 6 H 4 Y-4) 3 (Y = F, OMe, CF 3 , Me or Cl)] (10–14, 18, 20–23), show two successive one-electron reductions. Electrochemical data are also given for [Os(SC 6 F 5 ) 3 (PMe 2 Ph) 2 ] (19).

Thiolate complexes of osmium(IV): preparation of [Os(SR)4(PR′3)](R = C6F5, C6F4H-4, C6H4F-4 or Ph, R′= Ph; R = C6F5 or C6F4H-4, R′3= Me2Ph) and [OsCl(SC6F5)2(SC6H4X-3)(PMe2Ph)](X = F or CF3): crystal structures of [Os(SC6F4H-4)4(PPh3)] and [OsCl(SC6F5)2(SC6H4CF3-3)(PMe2Ph)]

The diamagnetic osmium(IV) complexes [Os(SR)4(PR′3)](R = C6F5, C6F4H-4, C6H4F-4, or Ph, R′= Ph; R = C6F5 or C6F4H-4, R′3= Me2Ph) and [OsCl(SC6F5)2(SC6H4X-3)(PMe2Ph)](X = F or CF3) have been prepared. The complex [Os(SC6F4H-4)4(PPh3)] has an essentially trigonal-bipyramidal structure with an apical PPh3 group [Os–P 2.391 (5), Os–Sap 2.414(5), mean Os–Seq, 2.207(7)A]. The structure of [OsCl(SC6F5)2(SC6H4CF3-3)(PMe2Ph)] is a somewhat distorted triagonal bipyramid with apical Cl– and PMe2Ph groups [Os–Cl 2.420(2), Os–P 2.340(2), mean Os–SC6F5 2.206(2), Os–SC6H4CF32.187(2)A]. The spectroscopic properties of these compounds are reported and the possibility of isomerism in solution is discussed.

Una secuencia de enseñanza/aprendizaje para los conceptos de sustancia y reacción química con base en la Naturaleza de la Ciencia y la Tecnología

Abstract Inside the international research project Teaching and Learning about Nature of Science and Technology: An experimental and longitudinal research (EANCyT, acronym in Spanish), a teaching/learning sequence is described, which has been designed to improve the comprehension of the Nature Of Science (nos) and Technology, trying to help students of the General Chemistry course in Undergraduate Education to learn adequate ideas around the scientific competences of «defining» and «modeling». This sequence involves students in an inquiry process related with the history and the definitions of the concepts «substance» and «chemical reaction», two of greatest importance in any chemistry course. Throughout the sequence, students will gradually improve the definitions of these two concepts from the macroscopic level to the nanoscopic one, trying them to be convinced that “defining is modeling”. The students will face the reading of essays on historical and experimental facets of both concepts. Additionally, it is analyzed here the carrying out of the sequence with a group of students on the first semester of 2012, and the changes that were done after this evaluation.

Representación algebraica del método de Kauffman para asignar números de oxidación

En este trabajo se presenta una formula adecuada para asignar numeros de oxidacion. La formula propuesta es la expresion matematica del metodo de Kauffman (1986) para asignar numeros de oxidacion en compuestos organicos. Sin embargo es aplicable a cualquier sistema quimico que pueda ser representado mediante estructuras de Lewis. Se discute un numero grande de sistemas representativos destacandose que mediante el uso de esta formula no hay necesidad de postular reglas arbitrarias ni excepciones ni numeros de oxidacion “no comunes”. Esta formula ademas de ser de amplia aplicacion, permite establecer una definicion mas precisa de numero de oxidacion en terminos de la conectividad de un elemento en un determinado sistema quimico.

Thiolate complexes of osmium(III) with tertiary phosphines and their dicarbonyl derivatives of osmium(II): X-ray crystal structure of trans,trans,trans-[Os(SC6F5)2(CO)2(PEt2Ph)2]

The preparation and physical properties of complexes of the type [Os(SC6F5)3(PR3)2] and [Os(SC6F5)2(CO)2(PR3)2](PR3= PMe2Ph, PMePh2, PEt2Ph, or PEtPh2), and the X-ray structure of trans,trans,trans-[Os(SC6F5)2(CO)2(PEt2Ph)2] are described.