Decay properties of the 19/2− isomers in113,117Sb

By means of the generalized centroid-shift method, the following half-lives were determined:T _1/2(3045 keV)=3.7±0.3 ns in¹¹³Sb using the reaction¹⁰⁴Pd(¹²C,p2n) as well asT _1/2 (1322.8 keV)=3.5±0.3 ns,T _1/2(2779.8 keV) =0.50±0.15ns,T _1/2(2874.9 keV)<0.2 ns andT _1/2(3072.9 keV)<0.1 ns in¹¹⁷Sb using the¹¹⁶In(α, 2n) reaction. Three-quasiparticle configurations of the type πd _5/2ν(h_11/2 d _3/2) in^113,117Sb are found to dominate in the wave functions of the 19/2^? states at 3045 and 2780 keV in¹¹³Sb and¹¹⁷Sb, respectively. TheB(E2, 19/2^? → 15/2^?) values in^113–119Sb are discussed.     

A convenient synthesis of long-chain 4-substituted benzyloxycarbonyl alkanethiols for the formation of self assembled monolayers on metal substrates

New 4-substituted benzyl esters of 16-mercaptohexadecanoic acid were prepared by developing a practicable synthetic procedure and using readily available staring materials. The compounds synthesized have been characterized by NMR, MS, IR spectra and elemental analysis. The mercapto derivatives are precursors for the formation of self-assembled monolayers on metal substrates. Dedicated to Professor Dr. Manfred Hesse on the occasion of his 70 ^th birthday     

Transition probabilities and the structure of some negative-parity states in 126,130Xe and 132Ba

The lifetimes of several negative-parity states in ^126,130Xe and ¹³²Ba have been determined by means of the generalized centroid-shift method. The reactions ^124,128Te(α, 2n) and ¹²²Sn(¹³C, 3n) have been used. Following results were obtained: T_1/2(2758 keV) = 1.3 ± 0.2 ns in ¹²⁶Xe, T_1/2 (2060 keV) = 0.20 ± 0.10 ns, T_1/2 (2104 keV) = 0.50 ± 0.10 ns, T_1/2 (2376 keV) = 0.30 ± 0.10 ns and T_1/2 (2973 keV) = 4.6 ± 0.4 ns in ¹³⁰Xe as well as T _1/2(2120 keV) = 0.40 _?0.10 ^+0.20 ns in ¹³²Ba. A systematics of the B(E2; 7 ₁ ^? ? 5 ₁ ^? ) values in the N = 76 nuclei is presented. Electric dipole and quadrupole transition rates are discussed in terms of octupole and quadrupole collectivity. The structure of the 5 ₁ ^? and 7 ₁ ^? states is considered. Nuclear reactions: ^124,128Te(α, 2n), E = 26 MeV, ¹²²Sn (¹³C, 3n), E = 53 MeV; measured E_{gg}, I_{gg}, γ-r.f. Deduced T_1/2, B(σL) in ^126,130Xe and ¹³²Ba. Ge detectors. Generalized centroid-shift analysis.     

Some M1 transition strengths in odd-A nuclei away from closed shells

By the in-beam application of the generalized centroid shift method, nanosecond half-lives have been determined for the first time: in ${}^{101}\text{Pd}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(1337.4}\text{keV}\text{) = 1.2}{}^{\mathrm{+0.6}}{}_{\mathrm{?0.3}}\text{ns and}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(261.0}\text{keV}\text{) = 0.7 ± 0.2}\text{ns}$ using the reaction $\text{(}{}^{12}\text{C}\text{,x}\text{n}\text{)}$, in ${}^{71}\text{As}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(147.5}\text{keV}\text{) = 0.85 ± 0.25}\text{ns}$ using the reaction (¹⁶ O, αp), in ${}^{91}\text{Nb}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(5455.3}\text{keV}\text{) = 1.2 ± 0.3}\text{ns}$ using the reaction (¹⁶O,2np), in ${}^{103}\text{Pd}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(244.0}\text{keV}\text{) < 0.2}\text{ns}$ and in ${}^{91}\text{Nb}\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{(3110.2}\text{keV}\text{) < 0.2}\text{ns}$ using the reaction P(α, xn). Some known nanosecond isomers in different nuclei produced as by-products have also been detected. In the nuclei investigated far away from closed shells with complex wave functions, M1 transitions are considered which would be l-forbidden in the pure shell model. A retarded $\text{Ml}\text{(+}\text{E}\text{2)}\text{25}\text{2}{}^{\mathrm{+}}\text{→}\text{23}\text{2}{}^{\mathrm{+}}$ transition in ⁹¹ Nb is considered as proceeding between possible multiparticle-hole configurations.     

Infrared and Raman vibrational spectroscopies reveal the palette of frescos found in the medieval monastery of Karaach Teke

Vibrational spectroscopy is applied on samples obtained from the excavation area of the medieval Monastery (10th century) of Karaach-Teke in Bulgaria. The results of the corresponding study, reveal the type of materials used for the creation of the wall-paintings and give evidence of Byzantine influence, a fact that further supports the well known impact of Byzantium on the technology and thematic-aesthetic features of iconography in Bulgaria during this era. In addition, the complementarity of FTIR and micro-Raman spectroscopies in the identification of pigments is indicated.     

Preparation of Chiral Hydroxy Carbonyl Compounds and Diols by Ozonolysis of Olefinic Isoborneol and Fenchol Derivatives: Characterization of Stable Ozonides by 1H-, 13C-, and 17O-NMR and Electrospray Ionization Mass Spectrometry

The allylic and homoallylic alcohols 1 – 8 , prepared from (+)-camphor and (−)-fenchone, were ozonized in Et₂O at −78° and treated with Et₃N or LiAlH₄ to give the chiral hydroxy carbonyl compounds 9 – 16 and the diols 17 – 24 , respectively (Scheme 1). In the case of the diols 19 and 24 , the formation of new chiral centers proceeded with high diastereoselectivity. These diols were prepared highly diastereoselectively also by LiAlH₄ reduction of the hydroxy carbonyl compounds 11 and 16a , respectively (Scheme 2). The absolute configuration of the new chiral centers in 19 and 24 was determined by X-ray and NMR methods. The ozonization of compounds 2 , 3 , 7 , and 8 provided the relatively stable hydroxy-substituted 1,2,4-trioxolane derivatives (ozonides) 37 – 40 (Scheme 5) which were characterized by ¹H- and ¹³C-NMR spectra, ESI-MS, and natural-abundance ¹⁷O-NMR spectra.     

Study of the system manganese(VII)-3,7-bis(dimethylamino)-phenothiazin-5-ium chloride-water-1,2-dichloroethane Using UV-spectrophotometry

The system manganese(VII)-3,7-bis(dimethylamino)-phenothiazin-5-ium chloride (MB)-water-1,2-dichloroethane has been studied using UV-spectrophotometry. The molar absorptivity of the complex is (3.86 ± 0.06) × 10⁴ L mol^?1 cm^?1 at 290 nm and the system obeys Beer??s law in the range 0.1?C0.99 ??g mL^?1 Mn(VII). The detection limit (DL) and quantitation limit (QL) of Mn(VII) determination were found to be 0.0146 and 0.049 ??g mL^?1, respectively. The composition of the complex is established as MB: MnO ₄ ^? = 1: 1. Extraction investigations of the system discussed were carried out. The characteristic values for the extraction equilibrium and the equilibrium in the aqueous phase was determined: extraction constant K_ex = (1.12 ± 0.05) × 10⁵, distribution constant K_D = 75.61 ± 0.1 and association constant ?? = (1.48 ± 0.08) × 10³. A new method has been developed for the microdetermination of manganese(VII) in plants and steels.     

6alpha-Angeloylplatynecine: a new alkaloid from Senecio nemorensis subsp. fuchsii (C.C. Gmelin) celak

The new alkaloid 6alpha-angeloylplatynecine, together with other four known pyrrolizidine alkaloids was identified from above ground parts of Senecio nemorensis subs. fuchsii.     

Hypepontine,a new quaternary alkaloid with antimicrobial properties

Abstract

New isoquinoline alkaloid hypepontine (1) together with a five known compounds, were identified in Hypecoum ponticum Velen, the partial synonym of Hypecoum procumbens L. The structure of the new substance was elucidated based on spectroscopic evidence. The tertiary and quaternary alkaloid mixtures as well as the isolated alkaloids were evaluated for their antibacterial and antifungal activity. The result revealed that the crude alkaloid mixture containing quaternary isoquinoline alkaloids showed potent antifungal and antibacterial activity.