Do Species Exist? Principles of Taxonomic Classification
Автор: Werner Kunz
Год издания:
A readily comprehensible guide for biologists, field taxonomists and interested laymen to one of the oldest problems in biology: the species problem. Written by a geneticist with extensive experience in field taxonomy, this practical book provides the sound scientific background to the problems arising with classifying organisms according to species. It covers the main current theories of specification and gives a number of examples that cannot be explained by any single theory alone.
Organometallic Compounds of Low-Coordinate Si, Ge, Sn and Pb. From Phantom Species to Stable Compounds
Автор: Lee Vladimir Ya.
Год издания:
Until recently the low-coordinate compounds of the heavier elements of group 14 were known only as transient, unstable species which were difficult to isolate. However recent developments have led to the stabilisation of these compounds and today heavier group 14 element cations, radicals, anions, carbene analogues, alkene and alkyne analogues and aromatics have all been prepared as highly reactive, stable, fully characterizable and readily available organometallic reagents. Organometallic Compounds of Low-Coordinate Si, Ge, Sn and Pb describes the chemistry of this exciting new class of organometallics, with an emphasis on their major similarities and differences with the analogous species in organic chemistry. Topics covered include include the synthesis, structure, reactions and synthetic applications of : Si-, Ge-, Sn and Pb-centered cations, radicals and anions heavy analogues of carbenes: silylenes, germylenes, stannylenes and plumbylenes heavy analogues of alkenes: disilenes, digermenes, distannenes, diplumbenes heavy analogues of alkynes: disilynes, digermynes, distannynes, diplumbynes, and their valence isomers heteronuclear derivatives: silenes, germenes, stannenes, silagermenes, silastannenes, germastannenes heavy analogues of alkenes of the type: >E14=E13-, >E14=E15-, >E14=E16 [where E13, E14, E15 and E16 are elements of the groups 13, 14, 15 and 16] cyclic compounds (three-, four-, five-, and six-membered rings) heavy analogues of 1,3-dienes, allenes and other cumulenes heavy analogues of aromatic compounds; including a comparison between organometallic and organic aromaticity Organometallic Compounds of Low-Coordinate Si, Ge, Sn and Pb is an essential guide to this emerging class of organometallic reagents for researchers and students in main group, organometallic, synthetic and silicon chemistry
