Dubnium element chemistry

The discoveries of all three of these elements were made at the beginning of the nineteenth century and were marked by initial uncertainty and confusion due, in the case of the heavier pair of elements, to the overriding similarity of their chemistries. (See p. 1282 for element 105, dubnium.)... 

Many chemists go to school for years and earn the top college degree before they make important discoveries in the lab, but James Andrew Harris took a different path. Harris graduated from college with a basic degree in chemistry, but then served in the Army and worked in a company lab before joining the team that discovered the transuranium elements rutherfordium and dubnium. 

Tiirler, A. Gas Phase Chemistry of the Transactinide Elements Rutherfordium, Dubnium, and Seaborgium , in Habilitation Thesis, Bern University (1999). 

For element 104 the names Kurchatovium (Ku) and Rutherfordium (Rf) were proposed by the groups at Dubna and Berkeley, respectively, thereby emphasizing their claim to the discoveries. The International Union on Pure and Applied Chemistry (lUPAC) has now decided on the following names element 104 Rutherfordium (Rf), element 105 Dubnium (Db), element 106 Seaborgium (Sg), element 107 Bohrium (Bh), element 108 Hassium (Hs), and element 109 Meitnerium (Mt). In the Periodic Table and nuclide charts we have thus used io4Rf. 106 8 107 > 108 So far no names have been... 

When a scientist discovered a new element in the early days of chemistiy, he or she had the honor of naming it. Now researchers must submit their choices for a name to an international committee called the International Union of Pure and Applied Chemistry before they can be placed on the periodic table. In 1997, the lUPAC decided on names for the elements from 104 through 111. These eight elements are now called rutherfordium (Rf), dubnium (Db), sea-borgium (Sg), bohrium (Bh), hassium... 

Abstract In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactmides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112. 

First studies of the aqueous phase chemistry of element 105 were conducted by Gregorich et al. (1988). Like Nb and Ta, Db was adsorbed on glass surfaces upon fuming with nitric acid. In 801 manually performed experiments, 24 a events due to the decay of 34 s Db or its 3.9 s Lr daughter including five aoc mother-daughter correlations were observed. In an attempt to study the extraction of the dubnium fluoride complex from 3.8 M HNO3/I.I M HF into methyl isobutyl ketone (MIBK), no decays attributable to Db could be observed. 

A source of great controversy was the naming of element 106. U.S. chemists endorsed the name seaborgium, in honor of the U.S. chemist Glenn Seaborg, who, over his career, led teams of scientists that synthesized 10 new elements. No person has ever equaled this achievement, so the Americans were confident that their proposal for the name of element 106 would easily gain acceptance from the worldwide scientific community. To their dismay, however, the International Union of Pure and Applied Chemistry (lUPAC) endorsed the name rutherfordium, in honor of Ernest Rutherford (see Section 5.3), for element 106. Moreover, the U.S. chemists were shocked by the lUPAC proposal that element 104 be named dubnium in honor of achievements at the research laboratory in Dubna, Russia. There were serious douhts as to the validity of the Russian chemists data. 

Abstract An overview over the chemical separation and characterization experiments of the four transactinide elements so far studied in liquid phases, rutherfordium (Rf), dubnium (Db), seaborgium (Sg), and hassium (Hs), is presented. Results are discussed in view of the position of these elements in the Periodic Table and of their relation to theoretical predictions. Short introductions on experimental techniques in liquid-phase chemistry, specifically automated rapid chemical separation systems, are also given. Studies of nuclear properties of transactinide nuclei by chemical isolation will be mentioned. Some perspectives for further liquid-phase chemistry on heavier elements are briefly discussed. 

Research on the chemistry of transactinide elements was resumed in the mid 1980s at Berkeley by the first study of element 105 in aqueous solution [123]. The a-particle emitter, 35-s Db, produced by the " Bk( 0,5n) reaction, served as a probe. The investigated chemical topic was the adsorption on glass in very strong nitric acid, a characteristic property of tantalum and niobium. Dubnium was found to share this property. Due to the very low production rate of Db, some 800 manually performed experiments were required to obtain a statistically satisfying result based on 24 a-decay events altogether. This example showed that automated, computer-controlled online procedures were needed for a broad exploration of the open territory. 

Chapter 6 presents the wealth of information obtained about properties of transactinides up to element 106, seaborgium, in the aqueous phase. This includes new and detailed information on the chemistry of elements 104, rutherfordium, and element 105, dubnium. 

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