Activation of a C−H Bond in Indene by [(COD)Rh(μ_2-OH)]_2

The air- and water-tolerant hydroxy-bridged rhodium dimer [(COD)Rh(μ_2-OH)]_2 cleanly activates the aliphatic C−H bond in indene to generate [(COD)Rh(η^3-indenyl)]. The mechanism involves direct coordination of indene to the dimer followed by rate-determining C−H bond cleavage, in contrast to the previously reported analogous reactions of [(diimine)M(μ_2-OH)]_2^(2+) (M = Pd, Pt), for which the dimer must be cleaved before rate-determining displacement of solvent by indene. Another difference is observed in the reactions with indene in the presence of acid: the Rh system generates a stable η^6-indene 18-electron cation, [(COD)Rh(η^6-indene)]+, that is not available for Pd and Pt, which instead form the η^3-indenyl C−H activation products. The crystal structure of [(COD)Rh(η^6-indene)] is reported

Oxidative aromatization of olefins with dioxygen catalyzed by palladium trifluoroacetate

Molecular oxygen can replace sacrificial olefins as the hydrogen acceptor in the palladium trifluoroacetate catalyzed dehydrogenation of cyclohexene and related cyclic olefins into aromatics. One of the major drawbacks of the homogeneous system is the tendency of the palladium trifluoroacetate to precipitate as palladium(0) at elevated temperatures. The use of better ligands affords catalysts that can operate at higher temperatures, although they are less reactive than palladium trifluoroacetate

A Versatile Ligand Platform that Supports Lewis Acid Promoted Migratory Insertion

A helping hand: Incorporation of Group 2 Lewis acids into a macrocycle appended to a phosphine ligand attached to a rhenium carbonyl complex promotes otherwise unfavorable transformations of coordinated CO (see scheme; M=Ca, Sr). These Lewis acids form relatively weak M-O bonds, thereby enabling release of organic products from the metal center

Strategy for Assessment of Online Course Discussions

The online teaching environment is a powerful interactive medium for promoting higher order thinking skills in students. Faculty have to adapt to this new medium by using components in online course tools (such as discussion boards) to create assignments that incorporate cooperative and collaborative learning. Assessment of this type of learning activity is different from tests used in traditional courses. This article discusses the role of discussions in online courses, provides a case for effective assessment needs, and using a sample case study discussion offers a strategy that can be used by faculty to assess online discussions

Reengineering an Information Security Course for Business Management Focus

This paper describes an information security course that evolved from a technology-focused legacy systems course to a current-topics Web commerce course for MBA students with an emphasis on business management issues faced by today\u27s networked organizations. The paper also describes the use of an online component, implemented to enhance student learning in a technology-based environment, which fostered interactivity and discussions among students. Using this course as a model, the paper presents a rationale for revising content and describes the framework, pedagogy and learning materials that were used in the course to meet the changing needs of information security management

Oxidation of Organometallic Platinum and Palladium Complexes Obtained from C−H Activation

η^3-Cyclohexenyl and -indenyl Pt(II) and Pd(II) diimine complexes, which are generated via C−H activation of cyclohexene and indene by Pt and Pd hydroxy dimers, are selectively oxidized by Br_2, Na_2PtCl_6, and CuCl_2 to give halogenated organic products along with well-defined Pd(II) and Pt(II) species

Development of courses for the maritime training institute of the Shipping Corporation of India

The, Shipping Corporation of India ltd. (SCI), is a public sector shipping organisation, registered at Bombay, owning and managing about 176 vessels of nearly six million tonnes DWT. In 1973, in order to meet the training needs of fleet and shore personnel, a training department was formed. A few short courses were developed and conducted by hiring space in various colleges and institutes at Bombay. With the growing needs of SCI, in regard to training of personnel and taking into account the requirements of, International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, 1978 (STCW 78), the idea was mooted to set up an, SCI Maritime Training Institute . Land was acquired at Powai, a suburb of Bombay, in 1982/83 and construction of the institute, has commenced in March 1985. It is expected that the institute would be functional by the end of 1986. In this paper, an attempt has been made to plan and develop the various courses which would be required to be conducted at the SCI Maritime Training Institute

Iridium(I) and Iridium(III) Complexes Supported by a Diphenolate Imidazolyl-Carbene Ligand

Deprotonation of 1,3-di(2-hydroxy-5-tert-butylphenyl)imidazolium chloride (1a) followed by reaction with chloro-1,5-cyclooctadiene Ir(I) dimer affords the anionic Ir(I) complex [K][{OCO}Ir(cod)] (2: OCO = 1,3-di(2-hydroxy-5-tert-butylphenyl)imidazolyl; cod = 1,5-cyclooctadiene), the first Ir complex stabilized by a diphenolate imidazolyl-carbene ligand. In the solid state 2 exhibits square-planar geometry, with only one of the phenoxides bound to the metal center. Oxidation of 2 with 2 equiv of [FeCp_2][PF_6] generates the Ir(III) complex [{OCO}Ir(cod)(MeCN)][PF_6] (3). Reaction of 3 with H_2 results in the liberation of cyclooctane and a species capable of catalyzing the hydrogenation of cyclohexene to cyclohexane. Displacement of cyclooctadiene from 3 can be achieved by heating in acetonitrile to form [{OCO}Ir(MeCN)3][PF_6] (4) or by reaction with either PMe_3 or PCy_3 to generate [{OCO}Ir(PMe_3)_3][PF_6] (5) or [{OCO}Ir(PCy_3)_2(MeCN)][PF_6] (6), respectively. 6 reacts with CO in acetonitrile to give an equilibrium mixture of 6 and [{OCO}Ir(PCy_3)_2(CO)][PF_6] (7) and with chloride to generate [{OCO}Ir(PCy_3)_(2)Cl] (8). The solid-state structure of 8 shows that the diphenolate imidazolyl-carbene ligand is distorted from planarity; DFT calculations suggest this is due to an antibonding interaction between the phenolates and the metal center in the highest occupied molecular orbital (HOMO) of the complex. 8 undergoes two successive reversible one-electron oxidations in CH_(2)Cl_2 at −0.22 and at 0.58 V (vs ferrocene/ferrocenium); EPR spectra, mass spectroscopy, and DFT calculations suggest that the product of the first oxidation is [{OCO}Ir(PCy_3)_(2)Cl]+ (8+), with the unpaired electron occupying a molecular orbital that is delocalized over both the metal center and the diphenolate imidazolyl-carbene ligand