IVB Metal Research Articles

The infrared intensities of the carbonyl stretching modes of a series of compounds, X3M—Mn(Co) 5 ( X = Cl, Br and I; M = Si, Ge and Sn)

The i.r. intensities of the carbonyl stretching vibrations of a series of compounds, X 3 M—Mn(CO) 5( X = Cl, Br and I; M = Si, Ge and Sn) with C 4ν, local symmetry around the manganese atom have been measured. The intensities of the A 1 mode of the four planar carbonyl groups increase as the halogen atom changes from Cl to I and/or the IVb metal atom changes from Si to Sn, and these increases correlate with the decrease of the metal-metal stretching force constants. This relationship between the i.r. intensities and the metal-metal stretching force constants can be interpreted in terms of the interaction of the IVb metal-manganese σ-orbitals with the π ∗ (radial) orbitals of the four planar carbonyl groups.

Ionicity, atomic radii, and structure in the layered dichalcogenides of group IVb, Vb, and VIb transition metals

Pauling's electronegativities are introduced in considerations of bond lengths, lattice constants, atomic radii, charge densities, structures, and heats of formation of the layered dichalcogenides of Groups IVb, Vb, and VIb transition metals. Strong correlations are found between these and the fractional ionic character of the metal-chalcogen bonds as defined by Pauling. A critical effective radius ratio is defined that separates trigonal prismatic and octahedral compounds.

Studies in boron hydrides—IX: Reaction of dicarbollide ions with some group IVb metal chelates

Reaction of the dicarbollide ions (3)-1,2- and 1,7-B 9C 2H 11 2− with the acetylacetonates of Zr(IV) and Hf(IV) gave (3)-1,2- and 1,7-B 9C 2H 12 − salts of M 4(acac) 4(OH) 11 +. The cation is The cation is formulated as a hydroxyl bridged species with terminal acetylacetonate groups.

The Infrared Spectra and Normal Coordinate Treatments of X3M–Mn(CO)5(X=Cl, Br, and I; M=Si, Ge, and Sn). II.

Abstract The infrared absorption spectra (2200–50 cm−1) have been measured for four metal-metal bonded molecules, Cl3Si–Mn(CO)5, Cl3Ge–Mn(CO)5, Br3Ge–Mn(CO)5, and I3Sn–Mn(CO)5. Vibrational normal coordinate analyses have been made for each of these molecules on the basis of a modified Urey-Bradley force-field. The calculated frequencies agree closely with validly-assigned frequencies. The metal-metal stretching force constant, K(M–Mn), or the F-matrix element, f(M–Mn), varies with the halogen atom, and increases as the electronegativity of X increases. The force constant, K(M–Mn), or f(M–Mn) depends also on the IVb metal atom, and increases in the order of: K(Si–Mn)≥K(Ge–Mn)>(Sn–Mn), or f(Si–Mn)≥f(Ge–Mn)>f(Sn–Mn). However, there is no clear relationship between the electronegativity of M and the K(M–Mn) or (M–Mn). These dependences of K(M–Mn) or f(M–Mn) on X and M are discussed, along with the bonding implications of the M–Mn bonds, on the basis of the sets of the force constants, or the sets of the F-matrix elements, and are interpreted in terms of the predominant σ-bonding framework of the M–Mn bonds.

Stability of reactive and refractory metal bor1des in ternary chromium-base alloys

Dispersion hardening by the Group IVb and Vb metal carbides has been demonstrated to improve the high temperature strength of chromium significantly 1, and has created interest in the similar use of the borides of these metals. The purpose of this work was to characterize the elevated temperature formation and stability of these borides in chromium-base alloys, about which little is currently known.

Hot-Pressing of Tantalum Carbide (I)

Carbides of Groups IVb, Vb, and VIb metals have high melting point, high hardness, and good electrical conductivity as well as good thermionic emissivity. Moreover, they exhibit high mechanical strength at elevated temperatures.Among these, ZrC, HfC, TaC and their solid solutions are important as high temperature materials because of their high melting points. But, since they have poor sinterability, few precise details are known about the powdered mixture or solid solution. This study, in a series of studies on TaC base materials for incandescent filaments, is aimed at development of sintered materials resistant against thermal shock.In this report the sintering properties in the binary system TaC-ZrC were studied by using a vacuum hot-pressing apparatus, since it was considered that the acceleration of the densification seems to control the properties, especially the mechanical properties of the sintered material.

Organometallic acetylene chemistry IV. Disubstituted acetylenes of the type PhP(CCMR 3) 2 and P(CCMR 3) 3

A series of organometallic acetylenes has been prepared of the type PhP(CCMR 3) 2 and P(CCMR 3) 3,where R is methyl and M is one of the Group IVb metals. These phosphinoacetylenes have been oxidized with hydrogen peroxideto give the corresponding phosphinyl acetylenes.

Organometallic acetylene chemistry : III. Disubstituted acetylenes of the type Ph 2PCCMR 3

A series of organometallic acetylenes has been prepared containing as substituents both diphenylphosphino and R 3M moieties, where R is either methyl or phenyl, and M is one of the Group IVb metals. These phosphinoacetylenes have been oxidized with both hydrogen peroxide and sulfur to give the corresponding phosphinyl and phosphinothioyl-acetylenes, respectively.

Nuclear magnetic resonance spectra of some arenechromium tricarbonyl complexes containing trimethyl Group IVb metal substituents

Nuclear magnetic resonance spectra of some arenechromium tricarbonyl complexes containing trimethyl Group IVb metal substituents

Studies of Metallic Hydrides. I. Synthesis of Stoichiometric Hydrides of Group IVb Metals

Abstract Formerly, hydrides of transition metals were generally treated as solid solutions or as hydrogen-occluding systems. It has been said that the elements in the IVb group of the periodic table, whose hydrides are typically metallic, do not form any stable hydride with a stoichiometric composition. The author intends to report the establishment of a process of synthesizing these hydrides, by which process the conditions necessary for the stoichiometric synthesis of IVb metal hydrides were determined.

Reactions of dialkynyl compounds of group IVB elements with metal carbonyls

Complexes of Group IVB elements and metal carbonyls of general formulae [R2MFe(CO)4]2, [R2MFe(CO)3PPh3]2, and R2M(C⋮C·R′)2[Co(CO)3]4(where R,R′= alkyl or aryl; M = Si, Ge, and Sn) have been obtained from the reactions of alkynyl compounds of Group IVB elements with metal carbonyls. The preparations, properties, and reactions of the secomplexes are described. The structures are inferred from infrared and nuclear magnetic resonance spectra.

Solid complexes with tetravalent metal ions and ethylenediamime tetra-acetic acid (EDTA)

Stable, crystalline acidic 1:1 EDTA chelates could be obtained with tetravalent germanium, tin, titanium, zirconium, hafnium and thorium. In acidic solution, the preparation of these slightly soluble compounds is straightforward—in contrast to other, previously reported methods—and yields very pure materials. All chelates are hydrated. In the case of octa-co-ordinated metals, the water is loosely bound, for hexa-co-ordinated metals, it is part of the molecule and has a strong influence on the infra-red spectra. This difference in water co-ordination has been shown by analytical data, infra-red spectra, and heat treatments. Addition of base leads to hydrolysis which is complicated for all Group IVB metal chelates, but which results in characteristic salt formation for both germanium and tin EDTA. Changes in the infra-red absorptions after hydrolysis and after heat treatment have been helpful for the interpretation of bonding in the original chelates.

Physico‐Chemical Studies of Hinokitiol. IV. Spectrophotometric Study of the Chelate Compounds of the Group IVB Metals with Hinokitiol

AbstractStability constants of titanium (IV), zirconium and thorium‐hinokitiolate chelates have been calculated from spectrophotometric data in 50% ethanol‐water solution at 25°. It has been found that the stability constant and the optimum pH of the various metal chelates increase with the increase in the atomic number of metals. The order of stability for the metals is the same as that found for other types of coordinating agents. Zirconium and thorium combine with four hinokitiolate ions, while titanium (IV) combines with only two hinokitiolate ions to form a chelate compound. A list of molar absorption coefficients is given and the photometric sensitivities of these metals with hinokitiol were determined.

Spectrophotometric, Polarographic and Solubility Behavior of the Chelate Compounds of the Group IVB Metals with Aromatic N-Nitrosohydroxylamines

Spectrophotometric, Polarographic and Solubility Behavior of the Chelate Compounds of the Group IVB Metals with Aromatic N-Nitrosohydroxylamines

The Preparation and Properties of the Group IV-B Metal Borohydrides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Preparation and Properties of the Group IV-B Metal BorohydridesH. R. Hoekstra and J. J. KatzCite this: J. Am. Chem. Soc. 1949, 71, 7, 2488–2492Publication Date (Print):July 1, 1949Publication History Published online1 May 2002Published inissue 1 July 1949https://doi.org/10.1021/ja01175a073RIGHTS & PERMISSIONSArticle Views741Altmetric-Citations137LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Illuminated fountains

Hard nitrides of group IVb metals can display not only gold-yellow, but also other fashionable colors as bronze, brown, violet, dark-blue and almost black by small variations of their stoichiometrical composition. The interest in this type of coatings for millinery goods such as watch cases, bracelets, lighters, jewels etc., is growing. The exact reproduction of tints remains delicate because of the extreme sensitivity of the human eye for small color differences. This fact limits the number of deposition methods available for decorative purposes to those where precise control of deposition parameters is possible. After a short review of the historical development of these coatings, their optical properties and other quality requirements, factors influencing color and various possibilities of process monitoring in reactive plasma-assisted physical deposition methods are discussed.