Booker W. O. Juma

Bio: Booker W. O. Juma is an academic researcher from Louisiana State University. The author has contributed to research in topics: Hydroformylation & Bite angle. The author has an hindex of 3, co-authored 3 publications receiving 272 citations.

A bimetallic hydroformylation catalyst: high regioselectivity and reactivity through homobimetallic cooperativity.

Abstract: The racemic and meso diastereomers of an electron-rich binucleating tetraphosphine ligand have been used to prepare homobimetallic rhodium norbornadiene complexes. The racemic bimetallic Rh complex is an excellent hydroformylation catalyst for 1-alkenes, giving both a high rate of reaction and high regioselectivity for linear aldehydes, whereas the meso complex is considerably slower and less selective. A mechanism involving bimetallic cooperativity between the two rhodium centers in the form of an intramolecular hydride transfer is proposed. Mono- and bimetallic model complexes in which the possibility for bimetallic cooperativity has been reduced or eliminated are very poor catalysts.

Symmetric hydrogen bonding in dimethylammonium hydrogen diphenyldiphosphonate.

Abstract: In the title compound, C2H8N+·C12H11O5P2−, pairs of hydrogen diphenyl­diphospho­nate anions form dimers across a twofold axis, with two symmetric O⋯H⋯O hydrogen bonds [O⋯O = 2.406 (3) and 2.418 (3) A]. The 12-membered ring thus formed has crystallographic 2 and quasi-222 symmetry. Cations on either side of the ring form N—H⋯O hydrogen bonds to the four extraannular O atoms, with N⋯O distances of 2.765 (2) and 2.748 (3) A.

Structures of nickel(II) bis‐ and trisphosphine diisothiocyanate complexes

Abstract: The structures of [P,P-diethyl-P'P'-diphenyl-1,2ethanediphosphine-P,P')di(thiocyanato-N)nickel(II), Ni(NCS) 2 (Et 2 PCH 2 CH 2 PPh 2 ) (1), and {bis[2-(diphenylphosphino)ethyl]ethylphosphine-P,P',P''}di(thiocyanato-N)nickel(II), Ni(NCS) 2 [EtP(CH 2 CH 2 PPh 2 ) 2 ] (2), have been determined. Complex (I) has square-planar geometry about Ni defined by the bidentate diphosphine ligand and two N-bonded thiocyanato ions. Thiocyanate coordination is nearly linear, with Ni-N-C angles of 170.2 (2) and 172.4 (2) o . The P-Ni-P bite angle of the chelating Ph 2 P(CH 2 ) 2 PEt 2 ligand is 87.05 (3) o

Hemilability of Hybrid Ligands and the Coordination Chemistry of Oxazoline‐Based Systems

Abstract: Ligand design is becoming an increasingly important part of the synthetic activity in chemistry. This is of course because of the subtle control that ligands exert on the metal center to which they are coordinated. Ligands which contain significantly different chemical functionalities, such as hard and soft donors, are often called hybrid ligands and find increasing use in molecular chemistry. Although the interplay between electronic and steric properties has long been recognized as essential in determining the chemical or physical properties of a complex, predictions remain very difficult, not only because of the considerable diversity encountered within the Periodic Table-different metal centers will behave differently towards the same ligand and different ligands can completely modify the chemistry of a given metal-but also because of the small energy differences involved. New systems may-even through serendipity-allow the emergence of useful concepts that can gain general acceptance and help design molecular structures orientated towards a given property. The concept of ligand hemilability, which finds numerous illustrations with hybrid ligands, has gained increased acceptance and been found to be very useful in explaining the properties of metal complexes and in designing new systems for molecular activation, homogeneous catalysis, functional materials, or small-molecule sensing. In the field of homogeneous enantioselective catalysis, in which steric and/or electronic control of a metal-mediated process must occur in such a way that one stereoisomer is preferentially formed, ligands containing one or more chiral oxazoline units have been found to be very valuable for a wide range of metal-catalyzed reactions. The incorporation of oxazoline moieties in multifunctional ligands of increasing complexity makes such ligands good candidates to display hemilabile properties, which until recently, had not been documented in oxazoline chemistry. Herein, we briefly recall the definition and scope of hemilabile ligands, present the main classes of ligands containing one or more oxazoline moieties, with an emphasis on hybrid ligands, and finally explain why the combination of these two facets of ligand design appears particularly promising.

Progress in hydroformylation and carbonylation

Abstract: The last 15 years of hydroformylation and carbonylation chemistry are reviewed, including technical and commercial aspects.

International Tables for X-Ray Crystallography

Abstract: International Tables for X-Ray Crystallography (Published for the International Union of Crystallography.) Vol. 1: Symmetry Groups. Edited by Norman F. M. Henry and Kathleen Lonsdale. Pp. xi + 558. (Birmingham: Kynoch Press, 1952.) 105s.