PARAMETER ESTIMATION IN MULTIRESPONSE MODELS

This article identifies a new Old English poetic motif, ‘The Departure of the Hero in a Ship’, and discusses the implications of its presence in Beowulf, the signed poems of Cynewulf and Andreas, a group of texts already linked by shared lexis, imagery and themes. It argues that the Beowulf-poet used this motif to frame his work, foregrounding the question of royal succession. Cynewulf and the Andreas-poet then adapted this Beowulfian motif in a knowing and allusive manner for a new purpose: to glorify the church and to condemn its enemies. Investigation of this motif provides further evidence for the intertextuality of these works

Synthesis, characterization and crystal structures of two new phenolic mannich bases

Two new Mannich bases, 5-methyl-2-((4-(pyridin-2-yl)piperazin-1-yl)methyl)phenol (1) and 5-methyl-2-((4-(4-nitrophenyl)piperazin-1-yl)methyl)phenol (2), were prepared and characterized structurally with elemental analysis, IR, UV and NMR spectroscopic techniques as well as single crystal X-ray diffraction. Compound I crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 6.6726(2) Å, b =   17.0542(6)   Å, c = 13.3222(4) Å, β = 100.832(1)°, V = 1489.00 (8) Å3, Z = 4, R1 = 0.0408, wR2 = 0.1143. Compound II crystallizes in the monoclinic space P21 with unit cell dimensions a = 5.9519(2) Å, b = 17.3315(8) Å, c = 15.7237(7) Å, β = 90.348(2)°, V = 1621.95(12) Å3, Z = 4, R1 = 0.0353, wR2 = 0.0965. Both compounds have their structures stabilized by hydrogen bonding and π∙∙∙π interactions.               KEY WORDS: Mannich base, Piperazine, X-ray diffraction, Hydrogen bonds Bull. Chem. Soc. Ethiop. 2019, 33(2), 341-348.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1

3-Methyl-1-phenyl-4-[(phen­yl)(2-phenyl­hydrazin-1-yl)meth­ylidene]-1H-pyrazol-5(4H)-one

The title compound, C23H20N4O, is a heterocyclic phenyl­hydrazone Schiff base with a pyrazole moiety. In the crystal, a variety of inter­actions occur, including N—H⋯π and π–π stacking between the phenyl ring of the phenyl­hydrazinyl group and its symmetry-generated equivalent [centroid–centroid distance = 3.6512 (7) Å]

4-[(4-Meth­oxy­benzyl­idene)amino]­benzene­sulfonamide

The title Schiff base compound, C14H14N2O3S, is non-planar, with a dihedral angle of 24.16 (7)° between the benzene rings. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link the mol­ecules into a layer parallel to (011). Intra- and inter­layer C—H⋯O inter­actions and π–π inter­actions [centroid–centroid distances = 3.8900 (9) and 3.9355 (8) Å] are also present

Standard and Null Weak Values

Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.Comment: 11 pages, 2 figures. To appear in Quantum Theory: A Two-Time Success Story: Yakir Aharonov Festschrif

1,5-Bis(2-methyl­phen­yl)-3-nitro­formazan

In the title compound, C15H15N5O2, the nitro O atoms are disordered over two sets of sites with an occupancy ratio of 0.75 (4):0.25 (4). Amine–imine tautomerism is observed in the formazan group. This was evident from the similar C—N bond distances in the formazan [1.319 (2) and 1.332 (3) Å], as well as the distribution of the imine proton in the Fourier difference map which refined to a 0.53 (3):0.47 (3) ratio. C—H⋯O and π–π inter­actions [centroid–centroid distances = 3.4813 (1) and 3.3976 (1) Å] are observed in the crystal packing

(E)-1-[2-(Methyl­sulfan­yl)phen­yl]-2-({(E)-2-[2-(methyl­sulfan­yl)phen­yl]hydrazinyl­idene}(nitro)­meth­yl)diazene

In the title compound, C15H15N5O2S2, the phenyl rings make dihedral angles of 4.03 (4) and 9.77 (5)° with the plane defined by the central N—N—C—N—N atoms (r.m.s. deviation = 0.010 Å). The C—S—C—C torsion angles of the methyl­sulfanyl groups with their respective phenyl rings are −7.47 (13) and −72.07 (13)°. The shortest centroid–centroid distance of 3.707 Å occurs between the two π-systems N—N—C—N—N and the benzene ring in the diazene 1-position. The H atom bound to the N atom is involved in intra­molecular N—H⋯N and N—H⋯S contacts, while the nitro O atoms are involved in inter­molecular C—H⋯O contacts