The absorption spectra of the gaseous monoxides of silicon, germanium and tin in the Schumann region

1954 ◽  
Vol 224 (1158) ◽  
pp. 374-388 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Ionization Potential ◽  
Absorption Spectra ◽  
Latent Heat ◽  
Satisfactory Agreement ◽  
Silicon Germanium ◽  
Silicon Monoxide ◽  
Dissociation Energies

The absorption spectra of the molecules SiO, GeO and SnO have been examined in the region 1250 to 2000Å. A number of new band systems have been found, and vibrational analyses have been carried out. The determination of the dissociation enérgies of these molecules is discussed: the values derived spectroscopically for SiO, GeO and SnO are 185∙ 0 ±6∙ 8 , 155∙ 8 ±5∙ 3 and 126∙ 0 ±4∙ 9 kcal (0° K) respectively. The values for GeO and SnO are in satisfactory agreement with the results of thermochemical work, but the result for SiO suggests that the value of the latent heat of sublimation of silicon is higher than has been suggested, and indicates L si ⋍100 kcal. The correlation between the states of carbon monoxide and of silicon monoxide is briefly considered, and a provisional value for the ionization potential of SiO, 10∙5 1 eV, is derived.

scholarly journals The determination of the heat of dissociation of fluorine and of the latent heat of vaporisation of lithium

1932 ◽  
Vol 136 (829) ◽  
pp. 76-82 ◽  
Keyword(s):  
High Temperature ◽  
Absorption Spectra ◽  
Latent Heat ◽  
Chemical Reactivity ◽  
Direct Method ◽  
Thermal Methods ◽  
Heat Of Dissociation

The heats of dissociation of chlorine, bromine, and iodine have been determined by thermal methods and estimated to be 58·9, 45·2 and 35·2 kilo-cals. respectively. But no data are yet known concerning the heat of dissociation of fluorine. It is very difficult to subject fluorine to the same treatment as Cl 2 , Br 2 and I 2 ( i. e ., heating to a high temperature in a sealed quartz bulb) owing to its extreme chemical reactivity, and hence no direct method of determining the heat of dissociation of fluorine has yet been devised. In the present paper I have determined it indirectly by interpretation of the absorption spectra of alkali fluorides (for the present only NaF and KF). A short theory of the experiment is given below.

scholarly journals Absorption spectra of the alkyl halides: energies of the C-I and C-Br bonds

1931 ◽  
Vol 133 (822) ◽  
pp. 430-439 ◽  
Keyword(s):  
Excitation Energy ◽  
Absorption Spectra ◽  
Satisfactory Agreement ◽  
Halogen Atom ◽  
Alkyl Halides ◽  
Thermochemical Data ◽  
Long Wave ◽  
Absorption Of Light ◽  
Wave Limit

It is to be expected that the alkyl halides will dissociate on absorption of light into alkyl residues and excited halogen atoms. Their absorption spectra are continuous, as is also the case with phenyl iodide, which liberates iodine under identical conditions. The C-I and C-Br linkages are certainly homopolar in the gas state. On Franck’s theory the long-wave limit of the absorption continuum should correspond to the heat of binding of C-I together with the excitation energy of the halogen atom. We would expect the alkyl halides to resemble the halogen hydrides in their behaviour, although with HI and HBr the long-wave limits are not very happily situated. The limit for HI is at 3320 Å., corresponding to a heat of dissocia­tion of 65,000 calories (the thermochemical heat is 69,000 calories) and the limit for HBr at 2640 Å. (97,000 calories, the thermochemical being 85,000). It is doubtful if these disagreements are entirely due to inaccuracy in the thermochemical data. The determination of these absorption limits seems to be a difficult matter. However, in the case of some of the alkyl halides we have been successful in obtaining very satisfactory agreement between the two sets of data, and have thought it worth while to give a brief account of our experi­mental method, and to reproduce at least one of our photometric records.

Relative Raman intensities of the totally symmetrical vibrations of the tetramethyls of carbon, silicon, germanium, tin and lead in the vapour state

1958 ◽  
Vol 246 (1244) ◽  
pp. 119-132 ◽  
Keyword(s):  
Carbon Atom ◽  
Satisfactory Agreement ◽  
Silicon Germanium ◽  
Central Carbon Atom ◽  
Vapour State ◽  
Germanium Tin ◽  
Bond Stretching ◽  
Central Carbon ◽  
State Frequency

An apparatus for the photographic determination of the relative intensities of Raman lines of gases and vapours at about 1 atm pressure is described. Results are given for the totally symmetric vibrations of the tetramethyls of carbon, silicon, germanium, tin and lead in the vapour state. Frequency-corrected relative intensities excited by the blue and violet mercury lines show satisfactory agreement. The intensity of the mode consisting principally of symmetrical methyl deformation is too low to be observed for C(CH 3 ) 4 , but increases (relative to the intensity of the C—H stretching mode) as the central carbon atom is progressively replaced by Si, Ge, Sn and Pb. Calculations show that this is accounted for by increased contributions from bond-stretching polarizability changes. Thus Wolkenstein’s assumption that the polarizability of a bond is not affected by changes of orientation remains a good approximation.

Modeling of Dynamic Loads on the Polished Rod of Pumping Unit in Case of Mulfunction of Rod Pump Operating

2014 ◽  
Vol 10 ◽  
pp. 95-101
Author(s):  
A.S. Topolnikov
Keyword(s):  
Multiphase Flow ◽  
Satisfactory Agreement ◽  
Model Simulation ◽  
Theoretical Modeling ◽  
Dynamic Loads ◽  
Plunger Pump ◽  
Proposed Model ◽  
Pumping Unit ◽  
Polished Rod

The paper presents the results of theoretical modeling of joined movement of pump rods and plunger pump and multiphase flow in a well for determination of dynamic loads on the polished rod of pumping unit. The specificity of the proposed model is the possibility of taking into account for complications in rod pump operating, such as leakage in valve steam, presence of gas and emulsion, incorrect fitting of plunger inside the cylinder pump. The satisfactory agreement of results of the model simulation with filed measurements are obtained.

Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides

1982 ◽  
Vol 47 (2) ◽  
pp. 503-508 ◽  
Author(s):  
Irena Němcová ◽  
Pavla Plocková ◽  
Tran Hong Con
Keyword(s):  
Absorption Spectra ◽  
Photometric Determination ◽  
Spectrophotometric Study ◽  
Ternary Complexes ◽  
Optimal Conditions ◽  
Bromopyrogallol Red ◽  
Binary Complexes

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.

scholarly journals Effects of Substituents on Photophysical and CO-Photoreleasing Properties of 2,6-Substituted meso-Carboxy BODIPY Derivatives

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 238-255
Author(s):  
Esther M. Sánchez-Carnerero ◽  
Marina Russo ◽  
Andreas Jakob ◽  
Lucie Muchová ◽  
Libor Vítek ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Absorption Spectra ◽  
Wavelength Range ◽  
Toxic Effects ◽  
Biological Research ◽  
In Vitro Experiments ◽  
Vast Array ◽  
Physiological Processes ◽  
Photochemical Properties

Carbon monoxide (CO) is an endogenously produced signaling molecule involved in the control of a vast array of physiological processes. One of the strategies to administer therapeutic amounts of CO is the precise spatial and temporal control over its release from photoactivatable CO-releasing molecules (photoCORMs). Here we present the synthesis and photophysical and photochemical properties of a small library of meso-carboxy BODIPY derivatives bearing different substituents at positions 2 and 6. We show that the nature of substituents has a major impact on both their photophysics and the efficiency of CO photorelease. CO was found to be efficiently released from π-extended 2,6-arylethynyl BODIPY derivatives possessing absorption spectra shifted to a more biologically desirable wavelength range. Selected photoCORMs were subjected to in vitro experiments that did not reveal any serious toxic effects, suggesting their potential for further biological research.

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