WorldCat Identities

Crosby, G. A.

Works: 16 works in 18 publications in 1 language and 26 library holdings
Roles: Author
Publication Timeline
Most widely held works by G. A Crosby
Intersystem crossing from higher excited states in complex molecules by Ruth E Whan( Book )

2 editions published in 1960 in English and held by 6 WorldCat member libraries worldwide

The general problem of intersystem crossing in complex molecules is discussed. Experimental techniques for detecting the phenomenon are evaluated, and criteria are established for selecting molecules for study
Irreducible representations of line groups : the dynamics of polymer chains by Katheryn Emanuel Lawson( Book )

2 editions published in 1961 in English and held by 4 WorldCat member libraries worldwide

The symmetries of infinite polymer chain molecules are discussed using the concept of line groups. Explicit directions are given for obtaining the irreducible representations of line groups employing the formalism developed for three-dimensional space groups. Line groups containing primitive and nonprimitive operations are discussed. Detailed considerations of the line group Vh are given with specific applications to the polyethylene molecule. Directions for generating symmetry-adapted vibrational coordinates for chain molecules are outlined
Luminescent Transition Metal Complexes in Magnetic and Electric Fields( Book )

1 edition published in 1975 in English and held by 1 WorldCat member library worldwide

During the grant period several important developments pushed the laboratory closer to its long term goal of designing materials with predetermined electrooptical properties. New materials were synthesized that were highly luminescent and amenable to spectroscopic investigation. Magnetic switching of luminescence was demonstrated and the effect of external fields on excited states was quantified. Geometrical parameters of transition metal complex excited states were also determined
Luminescence in Applied Magnetic Fields( Book )

1 edition published in 1989 in English and held by 1 WorldCat member library worldwide

Metal complexes and solids were synthesized and subjected to photoexcitation measurements under the influence of externally applied magnetic fields. The photoluminescence of complexes of rhodium (I) and iridium (I) displayed both field-induced emission bands and a many-fold shortening of the excited state lifetime. Both the decay rates and the induced emission band intensities showed a quadratic dependence on the applied field. A several fold shortening of the phosphorescence from the octaphosphitoplatinum (II) anion under an applied field (50 T) was also observed. Spectroscopic studies of several bis (N-heterocyclic) complexes of copper (I) were also concluded and complete group-theoretic assignments of the charge-transfer excited states were made. The technique of Thermal Modulation was perfected and applied to the study of the exited states of transition-metal complexes with near-degenerate emitting states
Structures and Dynamics of Luminescent Materials Including Lasers( Book )

1 edition published in 1971 in English and held by 1 WorldCat member library worldwide

Firm strides have been made in the development of methods of synthesis and purification for obtaining optically pure transition-metal complexes. Also general rules were established which summarize, catalog, and quantify the behavior of luminescent transition-metal ions. A significant accomplishment has been the formulation of a semiempirical quantum mechanical model that satisfactorily accounts for the observed optical behavior of these molecules and supplies important information about the role of spin-orbit coupling in complexes of the 4d and 5d elements. A final step forward has been the prediction - and demonstration - that complexes can be produced having optical parameters that are sensitive to the environment and may be modulated by external fields. In addition several advances are reported in instrumentation and methods of data reduction, specifically the construction of an apparatus to measure photoluminescence quantum yields and the successful determination of the efficiencies for over twenty transition-metal complexes of 4d and 5d elements, as well as the development of reliable methods of measuring decay times of luminescent crystals, plastics, and powders in the range 2-300K. (Author)
Synthesis and Spectroscopic Investigation of Inorganic Materials Possessing Unusual Electronic Properties( Book )

1 edition published in 1979 in English and held by 1 WorldCat member library worldwide

A comprehensive program of synthesis, chemical characterization and optical investigation of complexes of (nd)6 configuration possessing charge-transfer (CT) excited states was carried out. Approximately sixty molecules of Ru(II) and Os(II) were examined, a dozen of Ir(III) and six of Pt(IV). Absorption spectra (300 and 77 K), luminescence spectra (77 - 1.5 K) and temperature dependent decay times, quantum yields and emission spectra were examined. Several systems were subjected to intense magnetic fields at low temperatures. Several new luminescent systems useful for photochemical energy donors were discovered. The project carried the laboratory significantly further toward its stated goal of defining the principles by which new substances with potential value as media for electrooptical devices can be designed and synthesized in the laboratory
Assignment of the Charge-Transfer Excited States of Bis(N-Heterocyclic) Complexes of Copper(I)( Book )

1 edition published in 1989 in English and held by 1 WorldCat member library worldwide

Charge-transfer (CT) excited states of metal complexes are provoking intense study, particularly within the context of attempts to design efficient solar energy conversion processes. Since several classes of molecules containing the copper(I) ion have been observed to emit light in fluid solution, attention has been shown to induce electron transfer reactions, complete group theoretic assignments of the nature of the electronic states responsible for the visible absorption and emission spectra have not yet appeared. In this study we focus on the rigid matrix spectra of (Cu(NN)2) species (NN = substituted-2,2'-bipyridine or substituted-1,10-phenanthroline) and propose a group theoretical model to rationalize the results of extensive photophysical measurements on these interesting substances. Synthesis(Chemistry)
Magnetically-Induced Luminescence of (Ir(2=phos)2)C10 4( Book )

1 edition published in 1985 in English and held by 1 WorldCat member library worldwide

The intense luminescence of (Ir(2 double bond phos)2C104(2 double bond phos is cis-1,2-bis-(diphenylphosphino)ethylene) in a rigid glass matrix at 9.5 K was monitored while external magnetic fields (B sub max. = 6.7 Tesla) were applied. Radiative coupling to the ground state from a forbidden component was induced by the field
Structural Dependence of the Luminescence from Bis(substituted- benzenethiol)-(2,9-dimethyl-1,10-phenanthroline)zinc(2) Complexes( Book )

1 edition published in 1989 in English and held by 1 WorldCat member library worldwide

Changes in luminescence spectra and lifetimes of crystalline samples of the title compounds at 77 K are correlated with phase changes of the solids. The ease of conversion among phases is a general property of this class of materials. For bis (benzenethiol)-(2,9-dimethyl-1,10-phenanthroline)zinc (II) complete structure determinations were made of both phases. The attendant changes of the optical properties are ascribed to rotation of the planes of the two thiol rings on a single zinc ion from an approximately perpendicular to a nearly face-to-face conformation as the slowly heated crystal undergoes the phase change. The relevance of these results to the problem of charge-separation in solids is discussed
External Magnetic Field Effects on the Excited States of Iridium(I) and Rhodium(I) Complexes( Book )

1 edition published in 1987 in English and held by 1 WorldCat member library worldwide

Luminescences and excited state lifetimes have been measured for four iridium (I) and rhodium (I) complexes at 4 K as a function of magnetic field strength. Induced spectra exhibit a B-2 dependence while the lifetimes are function of B2
Observation of a Novel Low-Lying Excited State in Zinc Complexes( Book )

1 edition published in 1985 in English and held by 1 WorldCat member library worldwide

A novel low-lying excited state(s) has been observed from emission studies of complexes of the type M(BS)2(S-phen) (M = Zn(II), Cd(II); BS = benzene thiol; s-phen = substituted 1,10-phenanthroline) at 77 K. The state is tentatively assigned to a charge-transfer configuration in which the thiol donates charge through the closed d-shell to the N-heterocyclic state geometry with respect to the ground state. The state decays on the order of microseconds, but its spin signature has not yet been determined. Originator furnished keywords include: excited states, emission, luminescence, charge transfer, zinc(II) complexes
Structural Electronic Relationships in Polymeric Solids( Book )

1 edition published in 1983 in English and held by 1 WorldCat member library worldwide

The primary objective was to quantify the excited states of metal complexes so that their ultimate roles in photophysical, photochemical, and chemical processes could be assessed. The long-term goal was to arrive at a degree of sophistication such that materials with desired electrooptical properties could be designed at a molecular level and synthesized. A comprehensive study of osmium(II) (5d)6 complexes of D3 symmetry containing N-heterocyclic ligans was completed. The effect of solvents on the interactions of charge-transfer and ligand-field excited states was also quantified. A new series of complexes containing (nd)10 (n = 3,4) filled-shell metal ions was synthesized and studied spectroscopically revealing a new type of low-lying excited state. The structure of a typical example of this class of substances was determined by crystallography. A major accomplishment was the development of a multiple-state model for the lowest excited states of (nd)8 complexes, which was applied to several examples of rhodium(I) and iridium(I) complexes. Compounds of ruthenium(II) with N-heterocyclic tridentate ligands and D2d symmetry were also quantified spectroscopically
Determination of the Activation Barrier to Energy Transfer from 3 pi pi* to Charge Transfer Levels via Steady State and Transient Luminescence Measurements on Bis(4-Chlorothiophenol)(1,10-Phenanthroline)Zinc(II)( Book )

1 edition published in 1985 in English and held by 1 WorldCat member library worldwide

Recent studies on mixed ligand chelates of M(II)(BS)2(N-N) M(II) = Zn(II), Cd(II); BS = anion of a substituted benzenethiol; N-N = dinitrogen-heterocycle reveal the existence of multiple level emissions originating from different electronic configurations. The 6.5 K thermally modulated emission of Zn(4-Cl-PhS)2(phen) showed that the population of the emitting levels could be redistributed via heat pulses, a result that suggested an energy barrier between two accessible excited configurations. We report here an initial investigation of the temperature-dependence of both luminescence lifetimes and intensities of Zn(4-Cl-PhS)2(phen) in an attempt to measure the activation barrier between electronic configurations of dissimilar orbital parentages. The effect of temperature on the luminescence intensity and excited state lifetimes of the title compound is interpreted in terms of a barrier to the transfer of energy from the lowest 3 Pi Pi level to lower-lying charge-transfer levels. Fits of an Arrhenius expression to both lifetimes and relative intensities yield an activation energy and preexponential factor of approx. 140/cm and approx. 100,000/s, respectively
Fundamental investigations of luminescent materials( Book )

1 edition published in 1968 in English and held by 1 WorldCat member library worldwide

The main purpose of the research was to study the fundamental processes occurring in luminescent materials after the primary act of energy absorption. A second objective was to search for new luminescent substances of possible technological importance guided by the criteria established by concomitant fundamental studies on energy transfer. Numerous complexes of ruthenium(II), cobalt(III), osmium(II), iridium(III), rhodium(III), and platinum(IV) having pi-conjugated ligands were studied spectroscopically. Many of the materials were discovered to be highly-efficient, photochemically-stable, luminescent substances. Some of them exhibit properties which suggest potential value as active materials for electrooptical and laser devices. General experimental criteria were formulated which can be used to aid significantly in the task of making state assignments for new liminescent complexes of transition metals. Triplet states in rhodium complexes which are inaccessible by absorption measurements were located experimentally via emission spectroscopy. (Author)
Applications of Thermal Modulation in Luminescence Spectroscopy( Book )

1 edition published in 1987 in English and held by 1 WorldCat member library worldwide

The utility of thermally modulated emission (TME) spectroscopy as a technique for elucidating the properties of the excited states of molecules and complexes with near-degenerate excited electronic states is reviewed. A description of the TME method, its realm of application, and the type of information obtained are given. Particular emphasis is placed on the use of infrared heating as a tool for observing spectra in diverse media. Keywords: Metal Complexes
Luminescence from rhodium(lll) and iridium(111) complexes by G. A Crosby( Book )

1 edition published in 1969 in English and held by 1 WorldCat member library worldwide

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Audience level: 0.90 (from 0.76 for Irreducibl ... to 0.99 for Structural ...)

English (18)