Main group element

About: Main group element is a research topic. Over the lifetime, 1428 publications have been published within this topic receiving 49920 citations.

N-heterocyclic carbenes: a new concept in organometallic catalysis.

Abstract: N-Heterocyclic carbenes have become universal ligands in organometallic and inorganic coordination chemistry. They not only bind to any transition metal, be it in low or high oxidation states, but also to main group elements such as beryllium, sulfur, and iodine. Because of their specific coordination chemistry, N-heterocyclic carbenes both stabilize and activate metal centers in quite different key catalytic steps of organic syntheses, for example, C-H activation, C-C, C-H, C-O, and C-N bond formation. There is now ample evidence that in the new generation of organometallic catalysts the established ligand class of organophosphanes will be supplemented and, in part, replaced by N-heterocyclic carbenes. Over the past few years, this chemistry has been the field of vivid scientific competition, and yielded previously unexpected successes in key areas of homogeneous catalysis. From the work in numerous academic laboratories and in industry, a revolutionary turning point in oraganometallic catalysis is emerging.

Basic Inorganic Chemistry

Abstract: FIRST PRINCIPLES Some Preliminaries The Electronic Structure of Atoms Structure and Bonding in Molecules Ionic Solids The Chemistry of Selected Anions Coordination Chemistry Solvents, Solutions, Acids and Bases The Periodic Table and the Chemistry of the Elements THE MAIN GROUP ELEMENTS Hydrogen The Group IA(1) Elements: Lithium, Sodium, Potassium, Rubidium and Cesium The Group IIA(2) Elements: Beryllium, Magnesium, Calcium, Strontium and Barium Boron The Group IIIB(13) Elements: Aluminum, Gallium, Indium and Thallium Carbon The Group IVB(14) Elements: Silicon, Germanium, Tin and Lead Nitrogen The Group VB(15) Elements: Phosphorus, Arsenic, Antimony and Bismuth Oxygen The Group VIB(16) Elements: Sulfur, Selenium, Tellurium and Polonium The Halogens: Fluorine, Chlorine, Bromide and Astatine The Noble Gases Zinc, Cadmium and Mercury THE TRANSITION ELEMENTS Introduction to Transition Elements: Ligand Field Theory The Elements of the First Transition Series The Elements of the Second and Third Transition Series Scandium, Yttrium, Lanthanum and the Lanthanides The Actinide Elements SOME SPECIAL TOPICS Metal Carbonyls and Other Transition Metal Complexes with TT-Acceptor (TT-Acid) Ligands Organometallic Compounds Stoichiometric and Catalytic Reactions of Organometallic Compounds Bio-Inorganic Chemistry Index.

Main-group elements as transition metals

Abstract: The chemistry of heavier main-group elements such as aluminium, silicon and phosphorus is very different from that of the lighter ones such as boron, carbon and nitrogen, yet discussions of this topic have been dominated by comparisons with the light elements. Philip Power's review focuses on advances in chemistry of the heavier main-group elements that reveal them as having more in common with the transition metals than the lighter members of the main groups. The concept of heavier main-group elements as 'transition metals' is supported by recent work showing that many of the new compounds react with small molecules such as H2, NH3, C2H4 and CO under mild conditions and display potential as catalysts. The last quarter of the twentieth century and the beginning decade of the twenty-first witnessed spectacular discoveries in the chemistry of the heavier main-group elements. The new compounds that were synthesized highlighted the fundamental differences between their electronic properties and those of the lighter elements to a degree that was not previously apparent. This has led to new structural and bonding insights as well as a gradually increasing realization that the chemistry of the heavier main-group elements more resembles that of transition-metal complexes than that of their lighter main-group congeners. The similarity is underlined by recent work, which has shown that many of the new compounds react with small molecules such as H2, NH3, C2H4 or CO under mild conditions and display potential for applications in catalysis.

π-Bonding and the Lone Pair Effect in Multiple Bonds Involving Heavier Main Group Elements: Developments in the New Millennium

Abstract: This review is essentially an update of one entitled “πBonding and The Lone Pair Effect in Multiple Bonds Between Heavier Main Group Elements” which was published more than 10 years ago in this journal.1 The coverage of that survey was focused on the synthesis, structure, and bonding of stable compounds2 of heavier main group elements that correspond to the skeletal drawings reproduced in Tables 1 and 2. A row of numbers is listed at the bottom of each column in these tables. This refers to the number of stable complexes from each class that are currently known. The numbers in parentheses refer to the number of stable species that were known at the time of the previous review. Clearly, many of the compound classes listed have undergone considerable expansion although some remain stubbornly rare. The most significant developments for each class will be discussed in detail under the respective sections. As will be seen, there are also a limited number of multiple bonded heavier main group species that do not fit neatly in the classifications in Tables 1 and 2. However, to keep the review to a manageable length, the limits and exclusions, which parallel those used earlier, are summarized as follows: (i) discussion is mainly confined to compounds where experimental data on stable, isolated species have been obtained, (ii) stable compounds having multiple bonding between heavier main group elements and transition metals are not generally discussed, (iii) compounds in which a multiple bonded heavier main group element is incorporated within a ring are generally not covered, and (iv) hypervalent main group compounds that may incorporate faux multiple bonding are generally excluded. Such compounds are distinguished from those in Tables 1 and 2 in that they apparently require the use of more than four valence bonding orbitals at one or more of the bonded atoms. The remainder of this review is organized in a similar manner to that of the previous one wherein the compounds to be discussed are classified according to those summarized in Tables 1 and 2. The key unifying feature of almost all molecules discussed in this review is that they are generally stabilized by the use of bulky substituents which block associative or various decomposition pathways.3 Since the previous review was published in 1999, several review articles that cover parts of the subject matter have appeared.4