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Transition compounds

Spin-state transitions have been studied by the application of numerous physical techniques such as the measurement of magnetic susceptibility, optical and vibrational spectroscopy, the Fe-Mbssbauer effect, EPR, NMR, and EXAFS spectroscopy, the measurement of heat capacity, and others. Most of these studies have been adequately reviewed. The somewhat older surveys [3, 19] cover the complete field of spin-state transitions. Several more recent review articles [20, 21, 22, 23, 24, 25] have been devoted exclusively to spin-state transitions in compounds of iron(II). Two reviews [26, 27] have considered inter alia the available theoretical models of spin-state transitions. Of particular interest is the determination of the X-ray crystal structures of spin transition compounds at two or more temperatures thus approaching the structures of the pure HS and LS electronic isomers. A recent survey [6] concentrates particularly on these studies. [Pg.58]

This report has been written in order to demonstrate the nature of spin-state transitions and to review the studies of dynamical properties of spin transition compounds, both in solution and in the solid state. Spin-state transitions are usually rapid and thus relaxation methods for the microsecond and nanosecond range have been applied. The first application of relaxation techniques to the spin equilibrium of an iron(II) complex involved Raman laser temperature-jump measurements in 1973 [28]. The more accurate ultrasonic relaxation method was first applied in 1978 [29]. These studies dealt exclusively with the spin-state dynamics in solution and were recently reviewed by Beattie [30]. A recent addition to the study of spin-state transitions both in solution and the... [Pg.58]

Fig. 16. Schematic potential energy diagram of the low-lying ligand field states for d spin-state transition compounds. Full lines indicate the mechanism of forward and reverse LIESST effect. According to Ref. [135]... Fig. 16. Schematic potential energy diagram of the low-lying ligand field states for d spin-state transition compounds. Full lines indicate the mechanism of forward and reverse LIESST effect. According to Ref. [135]...
In solution studies, the modification of the equilibrium nuclear configuration appears primarily as a change of the partial molar volume A V° of the two spin states. The presently available values of AV° for spin conversions in solution are collected in Table 16. There is no apparent difference between the values for iron (II) and iron (III) spin transition compounds, the variation being... [Pg.134]

Table 17. Average metal-ligand bond lengths R for HS and LS isomers and bond length variation AR for complete HS <-> LS conversion of spin transition compounds... Table 17. Average metal-ligand bond lengths R for HS and LS isomers and bond length variation AR for complete HS <-> LS conversion of spin transition compounds...
In the following section, attention is directed towards these linear polynuclear Fe(II) spin crossover systems, whereas subsequent sections focus on mononuclear Fe(II) spin transition compounds containing chelating 1,2,4-triazole derivatives. [Pg.141]

Type of transition Compound T in K Type of transition Compound T in K ... [Pg.304]

An excellent introduction to the common features observed in electron spectra of non metallic surfaces and a simple discussion of the physical processes giving rise to these features is included in the review article by Holm and Storp (7). A good discussion from a practical introductory viewpoint is included in a Handbook of XPS (22). More exotic effects that lead to secondary lines of lower intensity such as multicomponent structure are more often encountered in transition metals and metallic oxides or transition compounds. These effects are discussed in more detail in Carlson (3) and Wertheim (23). [Pg.145]

Table 4. Properties of phase-transition compounds used for NMR temperature calibrations in the solid state... Table 4. Properties of phase-transition compounds used for NMR temperature calibrations in the solid state...
With the discovery of the damaging effects of CFCs, alternatives were developed that have many of the desirable characteristics of CFCs but are less stable in the lower atmosphere and less hkely to reach the stratosphere. These chemicals, called hydrochlorofluorocarbons (HCFCs), are similar in structure to CFCs but contain at least one hydrogen atom. For example, HCFC-22 is CF2HCI, and HCFC-123 is CF3CHCI2. Although these chemicals are thought to be less damaging to the ozone layer, they too can reach the stratosphere and lead to some depletion of O3. Thus they are viewed as transitional compounds to be used until better substitutes have been found. [Pg.272]

Proponents of mechanisms of the second group claim that the active initiation site resides at the transition metal atom and does not directly involve the second metal. The latter (e.g., AlEts) serves as an alkylation agent for the reduced transition compound (e.g., TiCls) to form the catalytically active species (e.g., Ti—R) (2). An increasing amount of evidence has been put forward to support such views. Since the weight of opinion is coming to favor these theories we wish briefly to cite three examples of this evidence. [Pg.434]

Table 1 Standard Redox Transitions Compounds Potentials of of Phosphorus... Table 1 Standard Redox Transitions Compounds Potentials of of Phosphorus...
The coordination number of a compound is defined as the number of attachment sites of the various ligands to the metal center. The valence-shell electron-pair repulsion (VSEPR) model does not work well for transition compounds having partially filled d-subshells. The Kepert model is sometimes used instead. As with the VSEPR model, the metal ion is assumed to be spherical with the ligands lying along the surface of the sphere. The ligands will repel one another for either electronic or steric reasons and will tend to distribute themselves around the sphere so as to avoid each other. In the Kepert model, the lone pair electrons (which are the low-lying d-electrons in the... [Pg.492]


See other pages where Transition compounds is mentioned: [Pg.57]    [Pg.59]    [Pg.66]    [Pg.67]    [Pg.67]    [Pg.83]    [Pg.83]    [Pg.143]    [Pg.156]    [Pg.321]    [Pg.222]    [Pg.88]    [Pg.151]    [Pg.315]    [Pg.107]    [Pg.97]    [Pg.369]    [Pg.222]    [Pg.147]    [Pg.315]    [Pg.453]    [Pg.3524]    [Pg.830]    [Pg.354]    [Pg.88]    [Pg.12]    [Pg.37]    [Pg.88]    [Pg.180]    [Pg.33]    [Pg.607]    [Pg.90]    [Pg.91]    [Pg.166]    [Pg.1158]   
See also in sourсe #XX -- [ Pg.62 , Pg.70 , Pg.73 , Pg.234 ]

See also in sourсe #XX -- [ Pg.62 , Pg.70 , Pg.73 , Pg.234 ]




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Absorption spectroscopy, lead compounds electronic transitions

Activation of Alkanes by Transition Metal Compounds

Active space, transition metal compounds

Alkylation of Nitro Compounds Using Transition Metal Catalysis

Antiferromagnetism and ferromagnetism in transitional-metal compounds

Band theory calculations transition metal compounds

Biaryl compounds, transition-metal-catalyzed

Biaryl compounds, transition-metal-catalyzed cross-coupling

Bonding in Transition Metal Compounds and Coordination Complexes

Bonding in transition metal compounds

Bonding mechanisms, transition metal compounds

Carbonyl compounds transition metal catalysts

Carbonyl compounds, Group 6 transition

Catalysis transition metal compounds

Chelated transition metal compounds

Chemical bonds transition metal compounds

Chiral compounds transition metal carbon-hydrogen

Chromium dimer transition metal compound

Clathrate inclusion compounds, phase transitions

Cluster compounds, chiral transition metal

Cobalt dimers, transition metal compound

Compounds magnetic transitions

Compounds of Transition Elements

Compounds of transition metals

Compounds with Bonds Between Transition and Main Group Metals

Compounds with Heteronuclear Transition Metal Bonds

Compounds with Homonuclear Transition Metal Bonds

Compounds with Transition Metals

Covalent bond transition metal compounds

Crotyl organometallic compounds chair-like transition states

Cyclopentadienyl transition metal compounds

Cyclopropenones with Transition-metal Compounds

Dative bonding, transition metal compounds

Density Studies of Transition Metal Compounds

Density functional theory transition metal compound structure

Dicarbonyl compounds, addition transition metal complexes

Dichalcogenides, transition metal layered compound

Dicyclopentadienyl compounds, transition

Dicyclopentadienyl compounds, transition metals

Effect of Heavy Atoms on Intercombinational Transitions in Aromatic Compounds

Electron density distributions transition metal compounds

Electron tunneling reactions between inorganic ion radicals and transition metal compounds

Electron-counting rules transition element compounds

Electronic Transitions and Lifetime of Excited States in Porphyrin-Based Compounds

Electronic spectroscopy transition metal compounds

Electronic structure transition metal compounds

Electronic transitions of organic compounds

Endothermic transition, liquid crystal compound

Examples of Coordination Compounds with Charge Transfer Transitions

Ferroelectric compounds, phase transitions

Fluorocarbon transition metal compound

Formyl transition metal compounds

Four GENERAL TRANSITION METAL COMPOUNDS

Germanium compounds transition-metal complexes

Group 14 compounds transition metal complexes

Hard Catalysis with Transition Metal Compounds

Heterogeneous Polymerization Catalysts Derived from Transition Metal Alkyl Compounds

Hydride transition metal compounds

In Stereochemistry of Optically Active Transition Metal Compounds Douglas

In Stereochemistry of Optically Active Transition Metal Compounds Douglas ACS Symposium Series American Chemical Society: Washington

Inorganic acids transition metal compounds

Insertion Reactions of Transition Metal-Carbon cr-Bonded Compounds. II. Sulfur Dioxide

Insertion Reactions of Transition Metal-Carbon cr-Bonded Compounds. II. Sulfur Dioxide and Other Molecules

Interatomic distances in transition metal compounds

Ionic bonding transition metal compounds

Ionic compounds transition elements

Ionic compounds transition state

Itinerant Magnetism Transition-metal Compounds

Lanthanide-transition metal compounds

Lead organic compounds transition-metal derivatives

Liquid crystals mesogenic compounds, phase transitions

Magnetic transitions intermetallic compound

Main Group Element-Transition Metal Mixed Compounds

Main group-transition metal cluster element compounds

Main group-transition metal cluster open compounds

Mercury compounds transition metal salts

Mixed-valence compounds intervalence transitions

Molecular Structures II Compounds of Transition Metals

Molecular orbitals transition metal compound

Molecular transition metal compounds

NMR of Transition Metal Compounds

Nickel compounds transition metal electronic structure

Non-transition element compounds

Nonmetals transition metal compounds

ORGANO-E(IV) COMPOUNDS OF TRANSITION METALS

Optical Activity in Silicon-Transition-Metal Compounds

Organo-Transition Metal Cluster Compounds

Organo-Transition Metal Compounds, Primary Photoprocesses of (Bock and von Gustorf)

Organo-Transition-Metal Compounds

Organoantimony transition metal compounds

Organoarsenic transition metal compounds

Organoarsenic transition metal compounds synthesis

Organobismuth transition metal compound

Organogermanium compounds transition metal complexes

Organogermanium compounds transition metal derivatives

Organolead compounds transition metal complexes

Organomagnesium transition-metal compounds, structures

Organometallic Compounds of Transition Metals

Organometallic compounds of transition elements

Organometallic compounds transition elements

Organometallic compounds, of transition

Organometallic compounds, transition metal use in heterocyclic synthesis

Organometallic compounds, transition metal, use

Organometallic radicals transition-metal compounds

Organosilicon compounds reaction with transition metals

Organotin compounds transition metal complexes

Other Spin-Forbidden Reactions of Transition Metal Compounds

PEROXO-TRANSITION METAL COMPOUNDS

Palladium compounds, electronic structure transition state

Peacock, R. D., Some Fluorine Compounds of the Transition Metals

Peroxy Compounds of Transition Metals

Phase transition temperatures compounds

Phase-transition compounds

Polymerization transition metal-carbon compounds

Prooxidant transition metal compounds

Quadrupole coupling constants transition metal compounds

Reactions of Isocyanides with Transition Metal Compounds

Reactions of Transition Metal Compounds with Alkylating or Arylating Reagents

Reactivity of Molecular Silicon-Transition-Metal Compounds

Reduction transition metal compounds

Replacement in Transition Metal Alkyl Compounds and Polymerization Activity

STEREOCHEMISTRY OF TRANSITION METAL COMPOUNDS

Samarium compounds transition

Silicon compounds transition metal-catalyzed silane reactions

Silicon-Transition-Metal Cluster Compounds

Silicon-transition-metal complexes halogen compounds

Soft Catalysis with Transition Metal Compounds

Spectra of Transition Element Compounds

Spectroscopic parameters transition-metal compounds

Spectroscopy of transition metal compounds

Stereochemistry and Bonding in Compounds of Non-transition Elements

Styrene with transition metal allyl compounds

Supramolecular transition metal compound

Synthesis of Transition Metal Nitrosyl Compounds

TCNQ compound, transition metal

TRANSITION-METAL ORGANIC COMPOUNDS

The Electronic Structure of Transition Metal Compounds

The Nature of Transition Metal Compounds Groups 4 to

The Photochemistry of Transition-metal Organometallic Compounds

The Transition Elements and Their Coordination Compounds

The Transition Metals and Their Compounds

Thioureas in synthesis of heterocycles Transition organometallic compounds

Transfer with transition metal compound

Transformation of Transition Metal Compounds in Reactions with Polymers

Transition Metal Compounds and Organic Ligands as Catalysts

Transition Metal Nitrosyl Compounds

Transition Metal-Catalyzed Couplings of Nonactivated Aryl Compounds

Transition Metal-Catalyzed Reactions of Diazo Compounds

Transition Metals Can Form a Variety of Coordination Compounds

Transition Metals Chemistry and Coordination Compounds

Transition Metals and Compounds

Transition Metals in GaN and Related Compounds

Transition alkyl compounds

Transition carbonyl compounds

Transition elements compounds)

Transition elements coordination compounds

Transition elements covalent compounds

Transition metal alkyl compounds

Transition metal alkyl compounds activity

Transition metal alkyl compounds heterogeneous polymerization catalysts

Transition metal alkyl compounds stereoregular polymerizations with

Transition metal alkyl compounds synthesis

Transition metal carbonyl compounds

Transition metal carbonyl nitrosyl compound

Transition metal chelate compounds

Transition metal complexes compounds formed with

Transition metal complexes trifluoromethyl compounds

Transition metal complexes with diazo compounds

Transition metal complexes with diazonium compounds

Transition metal compounds as catalysts

Transition metal compounds band structure

Transition metal compounds chemical

Transition metal compounds chemical bonding

Transition metal compounds chemical carbene complexes

Transition metal compounds chemical compound

Transition metal compounds chemical electron-sharing bonds

Transition metal compounds chiral manganese complex

Transition metal compounds computational techniques

Transition metal compounds covalent bonding

Transition metal compounds defects

Transition metal compounds ferroelectricity

Transition metal compounds lattice energies

Transition metal compounds magnetic properties

Transition metal compounds mechanical properties

Transition metal compounds nitrido

Transition metal compounds phase stability

Transition metal compounds phosphido

Transition metal compounds photochemistry

Transition metal compounds reaction mechanisms

Transition metal compounds relative stability

Transition metal compounds resolution

Transition metal compounds structure

Transition metal compounds superconductivity

Transition metal compounds, band theory

Transition metal compounds, group

Transition metal compounds, role

Transition metal compounds, use

Transition metal compounds, vapor pressure

Transition metal compounds, vibrational spectroscopy

Transition metal halides reactions with organolithium compounds

Transition metal hydrides carbonyl compounds

Transition metal hydrides unsaturated carbonyl compounds

Transition metal ions carbonyl compounds

Transition metal layered-compound

Transition metal macrocyclic compounds

Transition metal nitrides binary compounds

Transition metal nitrides ternary compounds

Transition metal organometallic compound

Transition metal silyl compounds

Transition metal surface compounds

Transition metal-Group 13 element complexes ionic compounds

Transition metal-gold compounds

Transition metals Organophosphorus compounds

Transition metals arsenic compounds

Transition metals bonded compounds

Transition metals cluster compounds

Transition metals compound name

Transition metals coordination compounds

Transition metals miscellaneous compound

Transition metals nitro compounds

Transition metals paramagnetic compounds

Transition metals vanadium compounds

Transition metals, carbon compounds

Transition metals, naming binary compounds

Transition metal—phosphine compounds

Transition organometallic compounds

Transition organometallic compounds heterocyclic synthesis, use

Transition organometallic compounds in heterocyclic synthesis, use

Transition polycatenar compounds

Transition-metal binary compounds

Transition-metal binary compounds Subject

Transition-metal compounds

Transition-metal compounds bonding characteristics

Transition-metal compounds point defects

Transition-metal organic compounds, alkyl

Transition-metal organic compounds, alkyl groups

Transition-metal silylene compounds

Transition-metal-based linear chain compounds

Transitions trihalide compounds

Use of transition organometallic compounds

Use of transition organometallic compounds heterocyclic synthesis

Use of transition organometallic compounds in heterocyclic synthesis

Zeolite-like Transition Metal Containing Porous Compounds

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