Louis J. Farrugia

Bio: Louis J. Farrugia is an academic researcher from University of Glasgow. The author has contributed to research in topics: Crystal structure & Charge density. The author has an hindex of 34, co-authored 243 publications receiving 49150 citations. Previous affiliations of Louis J. Farrugia include University of British Columbia & University of Jyväskylä.

Experimental charge density in the transition metal complex Mn2(CO)10: a comparative study

Abstract: A value is missing in the third row of the O3—C3 section of Table 3 on p. 238 of Farrugia et al. (2003). The missing value which should be in the fifth column is 13.757, and the remaining entries should be transfered to the next column along.

Experimental X-ray Charge Density Studies on the Binary Carbonyls Cr(CO)6, Fe(CO)5, and Ni(CO)4

Abstract: The experimental charge densities in the binary carbonyls Cr(CO)6 (1), Fe(CO)5 (2), and Ni(CO)4 (3) have been investigated on the basis of high-resolution X-ray diffraction data collected at 100 K. The nature of the metal−ligand interactions has been studied by means of deformation densities and by topological analyses using the Atoms in Molecules (AIM) approach of Bader. A detailed comparison between the experimental results and theoretical results from previous work and from gas-phase and periodic DFT/B3LYP calculations shows excellent agreement, both on a qualitative and quantitative level. An examination of the kappa-restricted multipole model (KRMM) for Cr(CO)6, using theoretically derived structure factors, showed it to provide a somewhat worse fit than a model with freely refined κ‘ values. The experimental atomic graphs for the metal atoms in 2 and 3 were found to be dependent on the multipole model used for that atom. In the case of compound 2, restriction of the multipole populations according t...

Synthesis of 2-Substituted Benzofurans and Indoles Using Functionalized Titanium Benzylidene Reagents on Solid Phase

Abstract: Titanium(IV) benzylidenes bearing a masked oxygen or nitrogen nucleophile in the ortho position were generated from thioacetals, using low-valent titanocene complex, Cp2Ti[P(OEt)3]2. Methylene acetal, alkyl ether, silyl ether, fluoro, tertiary amino, and N-alkyl, N-benzyl, N-prenyl, and N-silyl tert-butyl carbamate groups were tolerated in the titanium alkylidene reagents (Schrock carbenes). Aryl−chlorine bonds were stable to the titanium benzylidene functionality, but there was poor chemoselectivity for the reduction of the thioacetal in the presence of an aryl chloride. The titanium benzylidenes converted Merrifield and Wang resin-bound esters into enol ethers. The oxygen nucleophile was masked as a TMS ether, and when the resin-bound enol ethers bearing this ortho substituent were treated with 1% TFA in dichloromethane, benzofurans were released from resin in high yields. The chameleon catch strategy ensured excellent purity. In a similar way, N-alkylated and N-silylated tert-butyl carbamates were used...

Heteronuclear Clusters Containing Platinum and the Metals of the Iron, Cobalt, and Nickel Triads

Abstract: Publisher Summary This chapter reviews compounds containing polyhedral, linked polyhedral or planar arrangements of three or more directly bonded metal atoms, which are considered as clusters and compounds containing more open structures and chain structures. One underlying reason for the interest in heteronuclear clusters lies in their potential for site-specific reactivity at chemically differing metal atoms. The stoichiometry of the products is not rational, and the mechanisms clearly are very complicated, though once again these reactions, under experimental optimization, can provide very useful synthetic routes. An important consequence of the nonutilization of tangential orbitals is that platinum clusters often do not obey the normal electron counting rules and appear to be electron deficient. Clusters with chemically inequivalent hydrides often show hydride exchange. Several fluxional processes have been reported that imply some metal framework rearrangement. Isomerizations involving metal core rearrangements that are not fast on the nuclear magnetic resonance (NMR) time scale have also been observed. A few examples of tetranuclear species and several clusters containing platinum and two or more different metal atoms are reported. The metal–metal separations show considerable variation, and this has been attributed to the asymmetrical ligand distribution. Despite the general interest in bimetallic catalysts, there have been relatively few reports on catalysis by hetero-Pt clusters, either in the homogeneous phase or as supported catalysts.

Reactions of a {Mo16}-type polyoxometalate cluster with electrophiles: a synthetic, theoretical and magnetic investigation

Abstract: A medium-nuclearity mixed-valence polyoxomolybdate [H2Mo16O52]10− = {Mo16} (1a) was synthesized using an approach that employed protonated hexamethylenetetramine (HMTAH+) as counter ion and yielded (HMTAH)101a·34 H2O (1). The {Mo16} cluster anion exhibits significant nucleophilicity and traps electrophiles such as divalent transition metal ions, resulting in a family of isostructural compounds based on {Mo16M2}-type anions [M(H2O)8H2Mo16O52]6− (M = FeII (2), MnII (3), CoII (4)). The highly reactive nature of the {Mo16} system is also revealed by rearrangement and decomposition reactions of 1 to either slowly form a sodium-bridged heptamolybdate-based chain compound (5) when left in the reaction solution or, in the presence of very high concentrations of electrophiles, to heptamolybdate-based cluster compounds [M2(H2O)9Mo7O24]2− of the {M2Mo7}-type (M = FeII (6), MnII (7)). Compounds 1–7 were characterised by single crystal X-ray diffraction, elemental analysis, IR spectroscopy, magnetic susceptibility measurements, and density functional theory calculations.

WinGX suite for small-molecule single-crystal crystallography

Abstract: The category Computer Program Abstracts provides a rapid means of communicating up-to-date information concerning both new programs or systems and signi®cant updates to existing ones. Following normal submission, a Computer Program Abstract will be reviewed by one or two members of the IUCr Commission on Crystallographic Computing. It should not exceed 500 words in length and should follow the standard format given on page 189 of the June 1985 issue of the Journal [J. Appl. Cryst. (1985). 18, 189± 190] and on the World Wide Web at http://www.iucr. org/journals/jac/software/. Lists of software presented and/or reviewed in the Journal of Applied Crystallography are available on the World Wide Web at the above address, together with information about the availability of the software where this is known.

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

WinGX and ORTEP for Windows: an update

Abstract: The WinGX suite provides a complete set of programs for the treatment of small-molecule single-crystal diffraction data, from data reduction and processing, structure solution, model refinement and visualization, and metric analysis of molecular geometry and crystal packing, to final report preparation in the form of a CIF. It includes several well known pieces of software and provides a repository for programs when the original authors no longer wish to, or are unable to, maintain them. It also provides menu items to execute external software, such as the SIR and SHELX suites of programs. The program ORTEP for Windows provides a graphical user interface (GUI) for the classic ORTEP program, which is the original software for the illustration of anisotropic displacement ellipsoids. The GUI code provides input capabilities for a wide variety of file formats, and extra functionality such as geometry calculations and ray-traced outputs. The programs WinGX and ORTEP for Windows have been distributed over the internet for about 15 years, and this article describes some of the more modern features of the programs.