Na D line

All the alkali metals have characteristic flame colorations due to the ready excitation of the outermost electron, and this is the basis of their analytical determination by flame photometry or atomic absorption spectroscopy. The colours and principal emission (or absorption) wavelengths, X, are given below but it should be noted that these lines do not all refer to the same transition for example, the Na D-line doublet at 589.0, 589.6 nm arises from the 3s — 3p transition in Na atoms formed by reduction of Na+ in the flame, whereas the red line for lithium is associated with the short-lived species LiOH. 

Jongerius MJ, Van Bergen ARD, Hollander T, Alkemade CTH (1981) An experimental study of the collisional broadening of the Na-D lines by Ar, N2 and H2 perturbers in flames and vapor cells—I. The line core. J Quant Spectrosc Radiat Transfer 25 1-18... 

The quantity measured in the experimental work on the methane derivatives was the rotation of the Na D-line in ethanol solution (sometimes it was necessary to use another solvent, in which case a correction was applied). The sum (5), as well as its separate terms, was evaluated for 13 different choices of the set of ligands a,b,c,d,x. For eleven of these, the observed sum was less in absolute value than its statistical average calculated from the absolute values of the separate terms. For the other two (as well as for some of the eleven), the mixture contained molecules for which one would expect large deviations from T,rsymmetry, and/or dimerization. For those mixtures for which the sum (5) was small, a least-square fit was made to the data with a function of the form (2). This best fit was interpreted as the T -component, the remainder as the result of deviation from T -symmetry for each molecule. A fit was also made with functions of the form (1), with less quantitative success. 

The refractive index between gaseous phosphine at 0 °C and 760 mmHg and vacuum is 1.000789 when measured with white light. The refractive indices between liquid phosphine and air were found to be, for white light at 11 °C, 1.323 and for the Na-D-line at 17.5 °C, 1.317... 

Example 13.6. Sodium salts such as NaCl exposed to a hot flame of a Bunsen burner emit bright yellow light of the wavelengths 589.0 nm and 589.6 nm (so-called Na D-lines) which is used as a hint for the presence of sodium in analytical chemistry. When we observe the reflection of this light from a LB film made of barium stearate (n = 1.491) on a glass substrate (n2 1.52) it appears completely dark for a film thickness of about 100 nm. 

The structures are drawn in their zwitterionic forms with a net charge of 0. [a], optical rotation, Na d line ... 

Table 2.8 Index of Refraction Components na> nb. and nc (Measured at Na D Line, A = 589.29 nm) ...

A gas ionization source (e.g., Na vapor) is used, for instance, to measure the refractive index at the wavelength of the Na D-line emission. 

Table 11.3 Ultraviolet Cutoff Wavelength Ac (at which the Solvent in a Cell of Path Length L = 1 cm has an Absorbance of 1 unit). Dielectric Constant e, Scalar Refractive Index nD (Measured at 589 nm, the Na D-line), Dipole Moment ft (Debyes30), and Reichardt s31 Solvent Polarity Index ET...

Table 11.4 Magnetic Permeability Dielectric Constant (at 0 Hz) s/e0 and Scalar Index of Refraction nD (Measured at the Yellow Na D-Line 590 nm) Or Tensor Components of the Index of Refraction n0, ne = nig, n7 for Some Gases, Liquids, and Solids ...

Supersonic expansions have been used to form small metal aggregates, (2 < n < 4). Emphasis is placed on the analysis of bound-free transitions in these small metal clusters. Discussion focuses on the characterization of variously produced sodium supersonic expansions and the analysis of laser Induced atomic fluorescence resulting from the photodissociation of triatomic sodium clusters. We will consider (1) the nature of observed "fluctuation" bands corresponding to bound-free transitions involving a repulsive excited state which dissociates to yield (Na-D line) sodium atoms and ground state,, ... 

Figure 7. Continuation of spectra presented in Fig. 6. Key a, excitation spectrum (Ar ion pumped coumarin 7) showing Na B n — AT 2/ fluorescence b, Ps/i Na laser induced atomic fluorescence c, Pi/i laser induced atomic fluorescence and d, Fast photoluminescence scans indicating relative magnitudes of Na D-line and Noi B-X fluorescence (tick marks indicate v = 17,000 and 21,000 cm and indicates laser excitation frequency.

Figure 9. a Closeup of laser induced atomic fluorescence (see also Fig. 8) corresponding to the Ps/2 component of the Na D-line. b Na excitation... 

Figure 2. High resolution spectra of the Na D-line reversal from sapphire lamps operated at higher than normal Na pressures and lower than normal power loadings.

Therefore, when the helical twisting power is determined experimentally, its sign distinguishes enantiomers, its absolute value is compound specific. The information on the solute conveyed by the helical twisting power is on an equivalent level as the one from specific rotation [a]J (where the superscript T specifies the temperature and the subscript D denotes the frequency of the Na-D line), for instance... 

NaKCE t Na D line emission observed following excitation of... 

Polanyi and co-workers suggested in 1980 that emission might be observed from transition states. Emission observed as a wing on the Na D-line during the reaction F + Na2 — NaF + Na (3 P) has now been attributed by this group to FNaNa transition states in the process of separating to form NaF and Na cf. Maguire et al. 

The continuous vaporization of cosmic dust in the upper atmosphere leads to permanent metal atom layers at altitudes between 90-100 km. As pointed out in the introduction, the metals play an important role in the lower regions of the ionospheric region (see Fig. 2). The first manifestation of upper atmospheric metals was noticed early this century, when coarse spectra of the night sky revealed a line at 589.2 nm. In 1929, Slipher suggested that this emission line was due to sodium.Later studies refined the measurement to 589.3 nm, and tne identification of the Na-D emission line was definitely made. Shortly after, the first association of the Na-D line emissions in the nightglow with meteors entering the Earth s atmosphere was made by a number of authors.The actual chemical mechanism that can lead to optical emission of the Na-D line was first suggested by Chapman" ... 

Many attempts have been made to obtain spectra of meteor trails. Probably the best spectra ever obtained were by Millman and his colleagues at the Dominion Observatory. Figures 4 and 5 are a comparison of spectra stemming from a slow (probably Giacobinid) and a fast (Perseid) meteor, respectively. The spectrum of the low velocity meteor exhibits neutral emission lines of Mg, Fe, and Ca, the most abundant metals in most meteoroids. The strong Na D lines as well as a hint at excited N2 are also visible. By contrast, the spectrum of the high velocity meteor shows very... 

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