On the non-BoltzmannA-X emission in Na2 following laser excitation of theB state

A ¹Σ _u ⁺ -X ¹Σ _g ⁺ emission in Na₂ is observed following excitation ofB ¹π _u by various lines of an argon ion laser. The excitation energy ofB ¹π _u is collisionally transferred to the (2)¹Σ _g ⁺ which then radiatively populates theA ¹Σ _u ⁺ state. The Na vapour is contained in a stainless steel crossed heat pipe with Ar buffer gas and temperature around 600°C. For all laser lines except 4579 Å, the coarse features ofA-X emission are independent of the laser wavelength. However, at high resolution the finer differences between different laser line excitation are explained. Variousv′-v″ transitions in this emission are identified. Computer simulation is presented to help explain some features of this emission.     

Reinvestigation of the second negative (A 2 Π u−X 2 Π g) band system of O 2 +

TheA ² Π _ustate of O₂ ⁺ was earlier established as an inverted state contrary to previous assumptions. The rotational analysis of a few more bands of theA-X system of O₂ ⁺ has now been completed. These studies show that the spin-orbit coupling constantA in theA ² Π _ustate gradually varies with the vibrational quantum numberν and is found to be positive forν⩾6. It has also been observed that the spia-rotation interaction is not negligible in theA ² Π _ustate. The spin splitting constantγ is reported for various vibrational levels of this electronic state.     

Isotope shifts in the second negative bands of O 2 +

The second negative bands of O ₂ ⁺ , lying in the region 5000–1850 Å, have been photographed using oxygen enriched in¹⁸O. A study of the isotope shifts in the band heads revealed that thev″ numbering is to be increased by one unit whereas thev′ numbering remains unaltered. This change in vibrational numbering leads to a revision of the molecular constants of O ₂ ⁺ , especially of those in its ground state. These are discussed and the extension of the band system in the vacuum ultra-violet region reported. The possibility of developing a simple spectrographic method for the isotopic assay of oxygen using the isotope shifts in this band system is pointed out. The revised rotational and vibrational constants in theX ² II _g ground state of O ₂ ⁺ molecule are as follows :

$$\begin{gathered} \omega _e = 1903 \cdot 85 cm.^{ - 1} , \hfill \\ \omega _e x_e = 16 \cdot 18 cm.^{ - 1} , \hfill \\ B_e = 1 \cdot 6920 cm.^{ - 1} \hfill \\ and \hfill \\ r_e = 1 \cdot 1161 {\AA}. \hfill \\ \end{gathered} $$     

Indium Trichloride (InCl3) Catalyzed Synthesis of Fused 7‐Azaindole Derivatives Using Domino Knoevenagel‐Michael Reaction

An efficient and high yielding methodology developed for the synthesis of fused 7‐azaindole derivatives via one pot multicomponent assembly process of cyclic 1,3‐dicarbonyls with substituted aldehydes and 5‐amino‐1‐tert‐butyl‐1H‐pyrrole‐3‐carbonitrile. The transformation occurs via domino Knoevenagel‐ Michael reaction followed by intramolecular cyclization in the presence of catalytic amount of InCl₃ (10 mol %). Mild reaction conditions, easy isolation of products, and good to excellent yields in a shorter period of time are the silent features of present methodology. Structures of all the newly prepared compounds have been corroborated by various spectroscopic methods.     

A catalyst-and solvent-free multicomponent synthesis of 7-azagramine analogues via a Mannich type reaction

A catalyst-and solvent-free protocol for the synthesis of 7-azagramine analogues is described via a three-component Mannich type reaction between 7-azaindole, aromatic aldehydes and heterocyclic amines in acceptable to excellent yields. Structures of the compounds were confirmed satisfactorily by ¹H NMR, IR, mass, TOCSY, HSQC and HMBC spectral analyses.     

Relative photodissociation cross-section of NaCs molecule,using argon ion laser lines

Laser-induced photodissociation of NaCs molecule has been observed when a mixture of Na and Cs metal vapour in a glass cell was irradiated by most of the lines of an argon ion laser. The photodissociation results in the 3P state of Na atoms which is correlated with theF ¹Σ⁺ and G¹π molecular states of NaCs. Distribution of photofragments over fine structure components 3² P _3/2 and 3² P _1/2 of Na has been studied. The ratio of intensity ofD ₂ line (5890 Å) toD ₁ line (5896 Å) of Na varies from around 2 at 5145 Å to about 3.5 at 4579 Å. The relative photodissociation cross-section increases monotonically as the wave-length of laser light decreases from 5145 Å to 4579 Å. It is seen that the 4579 Å photon is about 200 times more effective than the 5145 Å photon in causing the photoreaction NaCs + (Ar⁺ photon) → Na*(3P) + Cs(6S).     

Evaluation of Virucidal Efficacy of Cold Plasma on Bacteriophage Inside a Three-Layered Sterilization Chamber

Plasma Chemistry and Plasma Processing - Traditional disinfection methods against pathogens have numerous shortcomings, and inventive methods like cold plasma are required for virus inactivation....     

Ketene dithioacetal mediated synthesis of 1,3,4,5-tetrasubstituted pyrazole derivatives and their biological evaluation

Abstract

Ketene dithioacetal mediated chemo- and regioselective synthesis of a series of novel 1,3,4,5-tetrasubstituted pyrazole derivatives (4a-l) integrated with a bioactive indole nucleus was achieved by reacting substituted 2-(1-methyl-1H-indole-3-carbonyl)-3,3-bis-(methylthio)-acrylonitrile (2) and substituted phenyl hydrazine hydrochloride (3) in the presence of a catalytic amount of anhydrous K₂CO₃ under reflux conditions. The structures were ascertained by ¹H NMR, NOESY, ¹³C NMR, FT-IR, and HRMS data. In vitro cytotoxicity evaluation of the synthesized compounds against MCF 7 (breast carcinoma) and normal Vero (monkey kidney) cell lines revealed that the compound 5-(5-Bromo-1-methyl-1H-indol-3-yl)-1-(4-cyano-phenyl)-3-methylsulfanyl-1H-pyrazole-4-carbonitrile (4k) showed significant cytotoxicity against MCF 7 (GI₅₀ = 15.6 µM) with low cytotoxicity against normal Vero cell line. Most of the synthesized compounds were also found to possess excellent anti-inflammatory and antioxidant (DPPH, NO, H₂O₂ and SOR) potential.     

Three photon resonant ionization in atomic potassium via S,P, D and F series Rydberg states

Single colour three photon resonant ionization (2 + 1) is observed in atomic potassium vapour in a heat pipe oven using an excimer laser pumped dye laser. Using wavelengths between 570 nm and 603 nm various²S and²D Rydberg states are populated by two photon excitation. Third photon of the same wavelength ionizes the atoms. Rydberg states up ton ⋍ 50 are observed. Electric field as low as 1 V/cm causes extensive Stark mixing of the states. This results in progressively higher three photon ionization signals via the perturbed²P and²F Rydberg states. The three photon ionization process is studied using both linearly and circularly polarized incident light. The experiment shows qualitatively that the²P Rydberg states are perturbed primarily by the²D states in the prescence of an external electric field and to a much smaller extent by²S states. This is also explained theoretically by calculating the Stark mixing coefficients under the Bates and Daamgard (1949) approximation. Implication for a similar effect in other alkali elements is discussed.     

Spectrographic determination of barium and strontium in geological samples

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Polarographic determination of Tergitol 08