Synthesis, characterization, and solid-state polymerization of cross-conjugated octatetraynes

2012 ◽  
Vol 90 (11) ◽  
pp. 994-1014 ◽  
Author(s):  
Yuming Zhao ◽  
Thanh Luu ◽  
Guy M. Bernard ◽  
Tyler Taerum ◽  
Robert McDonald ◽  
...  
Keyword(s):  
Solid State ◽  
Crystallographic Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
R And D ◽  
X Ray Crystallography ◽  
Topochemical Polymerization ◽  
Pendent Groups ◽  
C Nmr

Two series of cross-conjugated 1,3,5,7-octatetraynes (1a–1l and 6a–6d) have been synthesized. UV–vis spectroscopic analysis shows that pendent groups connected to the cross-conjugated skeleton have little effect on the λmax energies, irrespective of whether the groups are electron withdrawing or donating. A number of the isolated products readily give crystals suitable for X-ray crystallography, and the solid-state structural properties of five derivatives (1k, 1l, 6a, 6c, and 6d) have been examined by X-ray crystallographic analysis. Parallel packing of the polyynes in the solid state indicates that four of the five samples are potentially suitable for topochemical polymerization, based on solid-state packing parameters θ, R, and d. Attempts to effect a solid-state reaction have been explored through UV–vis and γ-ray irradiation as well as thermal heating. The course of these reactions was monitored by differential scanning calorimetry (DSC) analysis, as well as UV–vis and solid-state 13C NMR spectroscopy (for 1d, 1j, 1k, and 6d), which offered evidence of polymer formation from these reactions. Structural determination of the product(s), however, remains elusive.

scholarly journals Simple Methylcadmium Alkoxides

2007 ◽  
Vol 62 (10) ◽  
pp. 1339-1342 ◽  
Author(s):  
Surajit Jana ◽  
Tania Pape ◽  
Norbert W. Mitzel
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Molecular Formula ◽  
Equimolar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses ◽  
Solid State Structures ◽  
Structural Aspects ◽  
C Nmr

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.

The relative stabilities of PhE(NH-t-Bu)2 and PhE(μ-N-t-Bu)2EPh (E = As, Sb, and Bi): X-ray structures of {Li2[PhAs(N-t-Bu)2]}2 and PhE(μ-N-t-Bu)2EPh (E = Sb, Bi)

2003 ◽  
Vol 81 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Glen G Briand ◽  
Tristram Chivers ◽  
Masood Parvez
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Phenyl Group ◽  
Synthetic Approach ◽  
Relative Stabilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
In Trans ◽  
C Nmr

The reaction of PhECl2 with 2 equiv of LiHN-t-Bu has been studied for the series E = As, Sb, and Bi to determine the effect of the phenyl group on subsequent amine condensation processes. For PhAsCl2, the metathesis product PhAs(NH-t-Bu)2 4 was obtained as a colourless oil. Similar reactions involving PhECl2, where E = Sb or Bi, yielded the cyclodipnict(III)azanes PhE(μ-N-t-Bu)2EPh 5 (E = Sb) and 6 (E = Bi), respectively. Treatment of 4 with 2 equiv of n-BuLi produced the dilithium salt Li2[PhAs(N-t-Bu)2] 7a. Products 4, 5, 6, and 7a were characterized by 1H, 7Li (7a), and 13C NMR spectra, while 5, 6, and 7a were also structurally characterized by X-ray crystallography. Compound 7a is dimeric in the solid state via intermolecular Li···N and η6-Li···Ph interactions. The cyclodipnict(III)azanes 5 and 6 have similar structures, with the exocyclic phenyl groups in trans positions relative to the E2N2 ring. This synthetic approach provides a new route to the four-membered rings RE(μ-N-t-Bu)2ER (E = Sb, Bi) and the first example of a bis(organyl)cyclodibism(III)azane.Key words: arsenic, antimony, bismuth, amides, imides.

scholarly journals Solid-state tautomeric structure and invariom refinement of a novel and potent HIV integrase inhibitor

2013 ◽  
Vol 69 (3) ◽  
pp. 285-288 ◽  
Author(s):  
John Bacsa ◽  
Maurice Okello ◽  
Pankaj Singh ◽  
Vasu Nair
Keyword(s):  
Solid State ◽  
Integrase Inhibitor ◽  
Correlation Spectroscopy ◽  
Hiv Integrase ◽  
Acta Cryst ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molecular Charge ◽  
Intramolecular Hydrogen ◽  
C Nmr

The conformation and tautomeric structure of (Z)-4-[5-(2,6-difluorobenzyl)-1-(2-fluorobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]-4-hydroxy-2-oxo-N-(2-oxopyrrolidin-1-yl)but-3-enamide, C27H22F3N3O5, in the solid state has been resolved by single-crystal X-ray crystallography. The electron distribution in the molecule was evaluated by refinements with invarioms, aspherical scattering factors by the method of Dittrichet al.[Acta Cryst.(2005), A61, 314–320] that are based on the Hansen–Coppens multipole model [Hansen & Coppens (1978).Acta Cryst.A34, 909–921]. The β-diketo portion of the molecule exists in the enol form. The enol –OH hydrogen forms a strong asymmetric hydrogen bond with the carbonyl O atom on the β-C atom of the chain. Weak intramolecular hydrogen bonds exist between the weakly acidic α-CH hydrogen of the keto–enol group and the pyridinone carbonyl O atom, and also between the hydrazine N—H group and the carbonyl group in the β-position from the hydrazine N—H group. The electrostatic properties of the molecule were derived from the molecular charge density. The molecule is in a lengthened conformation and the rings of the two benzyl groups are nearly orthogonal. Results from a high-field1H and13C NMR correlation spectroscopy study confirm that the same tautomer exists in solution as in the solid state.

Two-bond 13C–13C spin-coupling constants in saccharides: dependencies on exocyclic hydroxyl group conformation

2021 ◽  
Author(s):  
Jieye Lin ◽  
Reagan J. Meredith ◽  
Allen G. Oliver ◽  
Ian Carmichael ◽  
Anthony S. Serianni
Keyword(s):  
Solid State ◽  
Torsion Angle ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Hydroxyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Spin Coupling Constants ◽  
C Nmr

13C-Labeled mono- and disaccharides were studied by X-ray crystallography and solid-state 13C NMR to determine the dependence of 2JC1,C3 in aldopyranosyl rings on the C1–C2–O2–H torsion angle, θ2, involving C2 of the C1–C2–C3 coupling pathway.

Determination of the absolute steric course of a solid-state photorearrangement by anomalous dispersion x-ray crystallography

1989 ◽  
Vol 111 (13) ◽  
pp. 4985-4986 ◽  
Author(s):  
Miguel Garcia-Garibay ◽  
John R. Scheffer ◽  
James Trotter ◽  
Fred Wireko
Keyword(s):  
Solid State ◽  
Anomalous Dispersion ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Absolute

scholarly journals Heterocyclic Hypervalent Iodine(III) Compounds with Fused Benziodazole and Tetrazole Rings (I-Substituted Tetrazolo[1,5-b][1,2]Benziodazoles)

2020 ◽  
Author(s):  
Rajesh Kumar ◽  
Kapil Dev Sayala ◽  
Lejla Lejla Camdzic ◽  
Maxime Siegler ◽  
Avichal Vaish ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hypervalent Iodine ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Thermal Stabilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
Derivatives Of ◽  
C Nmr

A series of heterocyclic hypervalent (HV) iodine(III) compounds containing fused tetrazole and benziodazole rings, i.e., derivatives of benziodazolotetrazole (BIAT) with various ligands (L) attached to the iodine atom (BIAT-L) were prepared and studied. They were characterized by <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy, ESI-HRMS, and X-ray crystallography. The thermal stabilities of all BIAT derivatives (L= Cl, OH, OAc, OMe) were studied and the degradation patterns as well as the enthalpies of degradation were measured by thermal gravimetric analysis coupled with differential scanning calorimetry. The reaction of various alkenes with BIAT-Cl in the presence of Cu(OTf)<sub>2</sub> at room temperature yielded chloro-tetrazolylated products. The oxidation of thioanisole with BIAT-Cl under various reaction conditions is also reported.

Modes of Xanthine Complexation to Dirhodium Tetrakis[(R)-α-methoxy-α- (trifluoromethyl)-phenylacetate] in Solution and in the Solid State

2001 ◽  
Vol 56 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Sven Rockitt ◽  
Rudolf Wartchow ◽  
Helmut Duddeck ◽  
Anna Drabczynska ◽  
Katarzyna Kiec-Kononowicz
Keyword(s):  
Solid State ◽  
Diffraction Analysis ◽  
Carbonyl Group ◽  
Enantiomeric Excess ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
X Ray ◽  
C Nmr

Abstract It is show n by IR and NMR studies that the xanthines 1-5 prefer a side-on com plexation to the chiral dirhodium tetrakis[(R)-α-methoxy-α-(trifluoromethyl)phenylacetatel (Rh*) in solution whereas carbonyl groups are involved in the solid state. For 6, at least the carbonyl group C-6 contributes to complexation in solution as well. A lternating strands of 6 and Rh* exist in the solid state as revealed by X-ray diffraction analysis described in detail. The determination of enantiomeric excess of the chiral xanthine 6 can easily be accomplished by the “dirhodium method ” (1H and 13C NMR in the presence of Rh*).

scholarly journals Heterocyclic Hypervalent Iodine(III) Compounds with Fused Benziodazole and Tetrazole Rings (I-Substituted Tetrazolo[1,5-b][1,2]Benziodazoles)

2020 ◽  
Author(s):  
Rajesh Kumar ◽  
Kapil Dev Sayala ◽  
Lejla Lejla Camdzic ◽  
Maxime Siegler ◽  
Avichal Vaish ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hypervalent Iodine ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Thermal Stabilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
Derivatives Of ◽  
C Nmr

A series of heterocyclic hypervalent (HV) iodine(III) compounds containing fused tetrazole and benziodazole rings, i.e., derivatives of benziodazolotetrazole (BIAT) with various ligands (L) attached to the iodine atom (BIAT-L) were prepared and studied. They were characterized by <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy, ESI-HRMS, and X-ray crystallography. The thermal stabilities of all BIAT derivatives (L= Cl, OH, OAc, OMe) were studied and the degradation patterns as well as the enthalpies of degradation were measured by thermal gravimetric analysis coupled with differential scanning calorimetry. The reaction of various alkenes with BIAT-Cl in the presence of Cu(OTf)<sub>2</sub> at room temperature yielded chloro-tetrazolylated products. The oxidation of thioanisole with BIAT-Cl under various reaction conditions is also reported.

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