VARIABLE PRESSURE OXYGEN-17 FTNMR AND STOPPED-FLOW KINETIC STUDY OF WATER EXCHANGE AND DMSO SUBSTITUTION ON SQUARE-PLANAR TETRAAQUA-PALLADIUM (II) AND -PLATINUM (II)

L'échange très lent d'eau sur Pt(H2O)2+4 a été étudié dans le domaine de températures 273 à 334 K et de pressions 0, l à 228 MPa, par RMN de l'oxygène-17, en suivant l'accroissement du signal de l'eau liée obtenu lors du mélange de solutions de platine (II) avec de l'eau enrichie en 17O. L'échange beaucoup plus rapide d'eau sur Pd(H2O)2+4 a été étudié dans le domaine de températures 240 à 345 K et de pressions 0, l à 260 MPa, par mesure de la largeur du pic de l'eau liée, à 27,11 et 48,78 MHz. La formation du complexe de Pd(H2O)2+4 avec le DMSO a été étudiée par stopped-f low, dans le domaine de températures 288 à 309 K, et de pressions 0, l à 175 MPa. Les résultats sont interprétés, dans les trois cas, en termes de modes d'activation associatifs (a).The very slow water exchange on Pt(H2O)2+4 was studied in the temperature range 273 to 334 K and pressure range 0.1 to 228 MPa by 17O FTNMR, following the increase in height of the signal from bound water observed when platinum(II) solutions are mixed with 170 enriched water. The much faster water exchange on Pd(H2O)2+4 studied in the temperature range 240 to 345 K and pressure range 0.1 to 260 MPa, by measuring the 17O FTNMR linewidths of the bound water resonance at 27.1 and 48.7 MHz. Complex formation between DMSO and Pd(H2O)2+4 was studied by stopped-flow, in the temperature range 288 to 309 K and pressure range 0.1 to 175 MPa. In the three cases, the results are interpreted in terms of associative activation modes (a)

Names and symbols for the transfermium elements

The recommendations (ref. 1) of the Commission on Nomenclature of Inorganic Chemistry (CNIC) on the nomenclature of the transfermium elements (101-109, inclusive) were considered by the IUPAC Bureau at Guildford (UK) in September 1995. As a result of the various criticisms of the recommendations and theway that they had been processed, the Bureau decided to adopt the recommendations as provisional and to circulate them to national/regional nomenclature centres in the normal way, with notices to be published innational/regional chemistry journals and magazines, requesting submission of comments to CNIC. In particular, the National Adhering Organizations (NAOs) were invited to express their views concerning the extant proposals for the names of these elements and the principles and traditions used to derive them. The response from the general chemical community was small, and the bulk of the replies came from nuclear scientists

Names and symbols of transfermium elements (IUPAC recommendations 1994)

The Transfermium Working Group (TWG) was set up in 1986 under the joint auspices of the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP). Its conclusions, duly endorsed by IUPAC and IUPAP, were published in the following three reports: 1. Criteria that must be satisfied for the discovery of a new chemical element to be recognized, Pure & Appl. Chem., 63, 879-886 (1991). 2. Discovery of the transfermium elements: Introduction to the discovery profiles, Pure & Appl. Chem., 65, 1757-1763 (1993). 3, Discovery of the transfermium elements: Discovery profiles of the transfermium elements, Pure & Appl. Chem., 65, 1764-1814 (1993). IUPAC went a stage further by inviting responses on reports 2 and 3 from the three major groups concerned, i.e., Lawrence Berkeley Laboratory, California; Joint Institute for Nuclear Research, Dubna; and Gesellschaft fur Schwerionenforschung , Darmstadt. These responses together with the TWG's reply to the responses were published unedited in Pure & Appl. Chem., Vol. 65, (1993), pp. 1815-1824