Pyrido[2,3-H]-2,6-naphthyridines. I. Synthesis and thermal reactions of the 2,2′bisacylazide of 3,3′ bipyridine

2 The2′-bisacylazide of 3,3′-bipyridine (1) has been synthesized from the (4,7)-phenantholine-5,6-dione ( 3 ) and the thermal decomposition of this new bisacylazide has been shown to give rise to the Curtius rearrangement and subsequent cyclization to the pyrido[2,3-h]-2,6-naph-thridinone ring system 8 .     

A measurement of the energy dependence of the inclusive yield of high-Pt events triggered by a large solid angle calorimeter

Large aperture calorimeter measurements of high transverse momentum events from 100, 200 and 340 GeV pp collisions are reported. Yields are higher by one to two orders of magnitude than the yield expected from uncorrelated statistical fluctuations in multiparticle events. The exponential slopes of the yields versus x_t exhibited a systematic change with $\text{s}\text{(x}{}_{\mathrm{<mtext>t</mtext>}}\text{= 2P}{}_{\mathrm{<mtext>t</mtext>}}\text{/}\text{s}\text{)}$. The events are shown to be more diffuse than pure jets as produced in e⁺e^? collisions. However, these events are consistent with a QCD-inspired 4-jet model.     

Magnetic neutron diffraction study of UGA3 and UGA2

The magnetic ordering of the intermetallic compounds UGa₃ and UGa₂ has been examined by time-of-flight neutron diffraction, and the nature of the magnetic order of these compounds is confirmed.     

Homolytic reactions of polyfluoroaromatic compounds. X. Biphenylyl radicals in the thermolysis of aroyl peroxides in polyfluoroaromatic solvents

The thermolyses of a number of aroyl peroxides in hexafluorobenzene, and of benzoyl peroxide in octafluorotoluene, gave the corresponding biaryls which were isolated by steam distillation. Mass spectrometry of the residues showed evidence of biphenylyl radicals arising from the arylation of the peroxides themselves or, possibly, of the derived aroic acids. Terphenyls, and the corresponding σ-intermediate radicals, could be found, and the relative molecular masses of the latter components showed that subsequent arylation of the main binuclear products was not the main source of terphenyls.     

Methotrexate analogs. 7. Synthesis of two higher homologs and a positional isomer of methotrexate diethyl ester as potential antitumor agents

Analogs of methotrexate diethyl ester ( 1 ) were prepared, in which the distances separating the ester functions from each other and from the carboxamide function of the p-aminobenzoate moiety were varied via the use of methylene groups as “spacers”. The diethyl esters 3 and 4 , with D,L-α-aminoadipate and D,L-α-aminopimelate side chains in place of L-glutamate, displayed approximately the same order of activity as compound 1 against bacterial and mammalian cells in culture, and were inhibitors of the enzyme dihydrofolate reductase. When given intraperitoneally to L1210 1eukemic mice at a dose of 120 mg./kg. q3d 1,4,7, compound 4 produced a 67% increase in survival and no evidence of toxicity, whereas methotrexate diethyl ester ( 1 ) gave a 44% increase in survival at a dose of 45 mg./kg. q3d 1,4,7 but was toxic at higher doses. The positional isomer 2 was inactive.     

Equilibria in complexes ofN-heterocyclic molecules,Part XV+. Intermediates in the reaction of cyanide with transition metal tris complexes of 1,10-phenanthroline, 5-nitro-1,10-phenanthroline and 2,2'-bipyridyl

Summary The Ru(phen)₃(CN)₂ · 6 H₂O, Ru(bipy)₃(CN)₂ · 6H₂O, Fe(phen)₃(CN)₂ · H₂O and Ru(5-NO₂P)₃(CN)₂ · 2 H₂O compounds have been isolated during the reaction of the parent cations with aqueous cyanide solutions. It is evident, that in each case, attack at the ligand has taken placevia the cyanide nucleophile, though the equilibrium constant for the formation of the Reissert-type species are widely different. The implications of the findings with respect to the known reaction kinetics of the parent ions in aqueous cyanide solution are discussed.Part 14: R.D. Gillard and P.A. Williams,Transition Met. Chem., 2, 109(1977)     

Electron refraction and light polarization effects in angle-resolved photoemission spectra of Cu surfaces using 45 eV radiation

Angle-resolved photoemission spectra of the low Miller-index faces of copper were taken with polarized 45 eV light for both surface normal and off-normal photoemission orientations. They reveal that low-energy photoelectrons emitted off-normal to the surface are strongly refracted toward the surface at the solid-vacuum interface; measured refraction angles are significantly (5&#x0303;0%) larger than predicted from a simple plane wave model. Furthermore, the spectra are found to be very sensitive to the orientation of the polarization of the exciting radiation with respect to the crystalline axes and the sample surface. Spectral dependence on light polarization is discussed in terms of direct transition selection rules for primary Mahan cones, influence of directionality on matrix elements, and direct transition contributions to the spectra from surface photoemission.     

A new study of Kπ scattering between 0.7 and 2 GeV/c2

We present new data on the reaction K⁺d → K⁺π^?p(p), at 5.44 GeV/c. This reaction is dominated by absorbed pion exchange and we have used the data to study K⁺π^? scattering between 0.7 and 2 GeV/c². We find the $\text{I=}\text{1}\text{2}$ s-wave Kπ phase shift increases approximately linearly with mass up to 1.45 GeV/c², and have evidence for a more rapid variation of the s-wave amplitude in the region of 1.5 GeV/c². The so-called “up” branches in the region of the K¹(890) and K¹(1400) are excluded, save for the possibility of narrow s-wave resonances of width <10 MeV/c². We have explained quantitatively every aspect of the data up to 2 GeV/c² with s-, p-, d- and f-waves, finding an f-wave resonance at a mass of ≈1.76 GeV/c² and with a width ≈300 MeV/c². We have obtained new resonance parameters for the K¹(1400) which differ substantially from the currently accepted values.