D- And F-block Chemistry

Cover images 0Murray Robertsonlvisual elements 1998-99, taken from the 109 Visual Elements Periodic Table Copyright 0The Royal Society of Chemistry 2002. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 605 Third Avenue. New York, N Y 10158-0012, (212) 850-601 I , fax (212) 850-6008, E-Mail: PERMREQ @ WILEYCOM. For ordering and customer service, call 1-800-CALL-WILEY. Library of Congress Cataluging-in-PublicationData: Library of Congress Cataloging-in-Publication Data is available. ISBN: 0-47 1-22476-6 Typeset in Great Britain by Wyvern 2 1, Bristol Printed and bound by Polestar Wheatons Ltd, Exeter 10987654321 Preface At first sight it may seem strange that metallic elements such as iron or copper, which we encounter in machinery or electrical wiring, might also be intimately involved in the function of living organisms. However, our very survival depends upon the particular chemical properties of these metallic elements, which belong to the d-block series known as the ‘transition metals’. To illustrate this point we might note that, after every breath we take, the oxygen we inhale is collected by the red protein haemoglobin present in our blood. The red color of blood arises from the presence of iron in this protein, and it is to this iron that the oxygen becomes attached. Through its attachment to hemoglobin, oxygen is transported in the blood to sites in the body where another protein containing both iron and copper effects its reduction. This releases energy as part of the process of respiration. What is so special about iron and copper that biology has selected them for these particular rbles? Why not nickel rather than iron? What do we need to know about their chemistry to understand why they are so specially suited to their particular functions? Apart from their rather immediate importance in maintaining life, transition elements are of major importance in enhancing the quality of our daily lives. Among the materials we encounter each day, many either contain transition elements or have been formed in processes which involve them. Even plastic materials may have required the use of a transition metal catalyst in their manufxture. In order to understand the biological rdes of transition metals, or develop new chemical processes involving them, it is first necessary to understand the principles which underly the chemistry of these elements. In a short text such as this it is not possible to