Dirk Mansfeld

Bio: Dirk Mansfeld is an academic researcher from Technical University of Dortmund. The author has contributed to research in topics: Bismuth & Adduct. The author has an hindex of 6, co-authored 7 publications receiving 188 citations.

Polynuclear Bismuth-Oxo Clusters: Insight into the Formation Process of a Metal Oxide

Abstract: The reaction of the bismuth silanolates [Bi(OSiR 2 R') 3 ] (R = R' = Me, Et, iPr; R = Me, R' = tBu) with water has been studied. Partial hydrolysis gave polynuclear bismuth-oxo clusters whereas amorphous bismuth-oxo(hydroxy) silanolates were obtained when an excess of water was used in the hydrolysis reaction. The metathesis reaction of BiCl 3 with NaOSiMe 3 provided mixtures of heterobimetallic silanolates. The molecular structures of [Bi 1 8 Na 4 O 2 0 (OSiMe 3 ) 1 8 ] (2), [Bi 3 3 NaO 3 8 -(OSiMe 3 ) 2 4 ].3 C 7 H 8 (3.3C 7 H 8 ), [Bi 5 0 Na 2 -O 6 4 (OH) 2 (OSiMe 3 ) 2 2 ].2 C 7 H 8 .2 H 2 O (4.2C 7 H 8 .2H 2 O), [Bi 4 O 2 (OSiEt 3 ) 8 ] (5), [Bi 9 O 7 (OSiMe 3 ) 1 3 ].0.5 C 7 H 8 (6.0.5 C 7 H 8 ), [Bi 1 8 O 1 8 (OSiMe 3 ) 1 8 ].2 C 7 H 8 (7.2 C 7 H 8 ) and [Bi 2 0 O 1 8 (OSiMe 3 ) 2 4 ].3C 7 H 8 (8.3C 7 H 8 ) are presented and compared with the solid-state structures of [Bi 2 2 -O 2 6 (OSiMe 2 tBu) 1 4 ] (9) and β-Bi 2 O 3 . Compound 2 crystallises in the triclinic space group P1 with the lattice constants a = 17.0337(9), b = 19.5750(14), c = 26.6799(16) A, a = 72.691(4), β = 73.113(4) and y = 70.985(4)°; compound 3.3C 7 H8 crystallises in the monoclinic space group P2 1 / n with the lattice constants a = 20.488(4), b = 22.539(5), c = 26.154(5) A and β = 100.79(3)°; compound 4.2C 7 H 8 .2H 2 O crystallises in the monoclinic space group P2 1 /n with the lattice constants a = 20.0518(12), b = 24.1010(15), c = 27.4976(14) A and β = 103.973(3)°; compound 5 crystallises in the monoclinic space group P2 1 /c with the lattice constants a = 25.256(5), b = 15.372(3), c = 21.306(4) A and β = 113.96(3)°; compound 6.0.5C 7 H 8 crystallises in the triclinic space group Pi with the lattice constants a = 15.1916(9), b = 15.2439(13), c = 22.487(5) A, a = 79.686(3), β = 74.540(5) and y = 66.020(4)°; compound 7.2C 7 H 8 crystallises in the triclinic space group P1 with the lattice constants a = 14.8295(12), b = 16.1523(13), c = 18.4166(17) A, a = 75.960(4), β = 79.112(4) and y = 63.789(4)°; and compound 8.3 C 7 H 8 crystallises in the triclinic space group Pi with the lattice constants a = 17.2915(14), b = 18.383(2), c = 18.4014(18) A, a = 95.120(5), β = 115.995(5) and y = 106.813(5)°. The molecular structures of the bismuth-rich compounds are related to the CaF 2 -type structure. Formally, the hexanuclear [Bi 6 O 8 ] 2 + fragment might be described as the central building unit, which is composed of bismuth atoms placed at the vertices of an octahedron and oxygen atoms capping the trigonal faces. Depending on the reaction conditions and the identity of R, the thermal decomposition of the hydrolysis products [Bi n O l (OH) m -(OSiR 3 ) 3 n - ( 2 l - m ) ] gives α-Bi 2 O 3 , β-Bi 2 O 3 , Bi 1 2 SiO 2 0 or Bi 4 Si 3 O 1 2 .

The First Metal‐Oxo Cluster Containing Lithium and Bismuth

Abstract: The reaction of [Bi(OtBu)3] with LiOSiMe3 gave the heterobimetallic bismuth-oxo cluster [Bi3Li5(μ5-O)2(μ3-OSiMe3)2(μ3-OtBu)2(μ2-OtBu)6] (1) after elimination of Me3SiOSiMe3. The cage compound 1 is the first example of a mixed-metal alkoxide/siloxide composed of lithium and bismuth. Crystals of 1·2 C7H8 and 1·1.5 THF suitable for X-ray single crystal structure analysis were obtained by crystallisation from toluene and THF, respectively. Both solvates crystallise in the orthorhombic space group Pmmn with Z = 2. The lattice constants are a = 16.267(3) A, b = 17.126(3) A and c = 12.155(2) A (1·2 C7H8) and a = 16.353(2) A, b = 17.156(1) A and c = 12.256(1) A (1·1.5 THF). In both compounds the solvent molecules occupy channels along the c-axis. The basic molecular unit is best described as a face-sharing double cubane [BiLi5(μ4-O)2(μ3-OSiMe3)2(μ3-OtBu)2] which is coordinated by two [Bi(OtBu)3] molecules. The compound is kinetically labile in solution and readily decomposes in 1,1,2,2-tetrachloroethane with elimination of 1,1,2-trichloroethylene. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Electrospray mass spectrometry (ESI-MS) in the study of metal-ligand solution equilibria.

Abstract: In the 20 years, since the introduction of electrospray mass spectrometry (ESI-MS), the use of this technique in various fields of inorganic, organometallic, and analytical chemistry has been steadily increasing. In this study, the application of ESI-MS to the study of metal–ligand solution equilibria is reviewed (till 2004 included). In a first section, advantages and drawbacks of ESI-MS in this type of application are described. Subsequently, a list of ca. 300 studies is reported, in which ESI-MS was used to give number and stoichiometry of the species at equilibrium, or also to estimate their stability constants. All studies are classified according to the metal ions under examination. Other related applications, such as host–guest interactions and metal ion-protein binding studies, are briefly reviewed as well. © 2005 Wiley Periodicals, Inc., Mass Spec Rev 25:347–379, 2006

Anion-centered tetrahedra in inorganic compounds.

Abstract: Sergey V. Krivovichev,*,†,‡ Olivier Mentre,́ Oleg I. Siidra,† Marie Colmont, and Stanislav K. Filatov† †St. Petersburg State University, Department of Crystallography, University Emb. 7/9, 199034 St. Petersburg, Russia ‡Institute of Silicate Chemistry, Russian Academy of Sciences, Makarova Emb. 6, 199034 St. Petersburg, Russia UCCS, Equipe de Chimie du Solide, UMR CNRS 8181, ENSC LilleUST Lille, BP 90108, 59652 Villeneuve d’Ascq Cedex, France