Hydroboration of 1,1'-Bi(cyclopent-1-ene) and 3,3'-Biindene: Experimental and Theoretical Study

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1611-1626 ◽  
Author(s):  
Jaroslav Kvíčala ◽  
Ondřej Baszczyňski ◽  
Alena Krupková ◽  
Denisa Stránská
Keyword(s):  
Single Crystal ◽  
Nmr Spectra ◽  
Theoretical Study ◽  
Major Product ◽  
Reaction Conditions ◽  
Dft Methods ◽  
X Ray ◽  
Preferential Formation ◽  
H Nmr

Hydroboration of bi(cyclopent-1-ene) (1) or 3,3'-biindene (2) with borane, thexylborane or (-)-isopinocampheylborane afforded, regardless of reaction conditions, meso-isomers of polycyclic 1,4-diols 3a, 4a as the main products. No reaction was observed with 9-BBN. The structure of the major product 4a, as well as of the minor racemic product 4b was assigned based on 1H NMR spectra of the corresponding Mosher's diesters 5a-5c. Finally, the stereochemistry of the product 4a was confirmed by a single-crystal X-ray analysis of the corresponding dimesylate 6. To elucidate preferential formation of the meso-isomers, complexes of monohydroborated intermediate with borane were studied theoretically by DFT methods.

Bis(imidazol-2-yl)phosphinic acid hemihydrate, [(C3H3N2)(C3H4N2)PO2].(1/2)H2O

1989 ◽  
Vol 67 (6) ◽  
pp. 1051-1060 ◽  
Author(s):  
Helen E. Howard-Lock ◽  
Colin J.L. Lock ◽  
Sarah Penny ◽  
Mary A. Turner
Keyword(s):  
Single Crystal ◽  
Vibrational Spectroscopy ◽  
Title Compound ◽  
Phosphinic Acid ◽  
Major Product ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
H Nmr ◽  
Zwitterionic Form

The title compound was obtained as the major product of our handling of the literature preparation of tris(imidazol-2-yl)phosphine. The compound was characterized by 1H NMR, mass and vibrational spectroscopy. The structure was determined by single crystal X-ray diffraction. Crystals were triclinic, [Formula: see text], a = 7.677(1), b = 12.658(2), c = 10.072(2) Å, α = 91.18(1),β = 114.44(1),γ = 99.49(1)°, Z = 4. Intensities were measured on a Syntex P21 diffractometer with MoKα radiation and 3088 reflections were used to determine the structure. R = 0.0698, Rw = 0.0534. The phosphinic acid exists in the solid as the zwitterionic form and bond lengths and angles are normal. Keywords: tris(imidazol-2-yl)phosphine, X-ray structure, bis(imidazol-2-yl)phosphinic acid hemihydrate.

Unexpected formation of a triphyrin in the reaction of dibromodipyrromethene and N,N-dimethylaminoethanol

2014 ◽  
Vol 18 (08n09) ◽  
pp. 721-726
Author(s):  
Soji Shimizu ◽  
Shoma Hirokawa ◽  
Nagao Kobayashi
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Visible Region ◽  
Conformational Flexibility ◽  
Major Product ◽  
Single Crystal Diffraction ◽  
Broad Absorption ◽  
Unexpected Formation ◽  
X Ray ◽  
H Nmr

A novel triphyrin was unexpectedly formed as a major by-product in the synthesis of meso-aryl-substituted dibenzo-5,10,15-triazaporphyrin from meso-aryl-substituted 1,9-dibromodipyrromethene and 5,6-diaryl-substituted 1,3-diiminoisoindoline in the presence of N,N-dimethylaminoethanol (DMAE). X-ray single crystal diffraction analysis elucidated that the terminal α-positions of this triphyrin were bridged by an N-methylaminoethoxy chain, which plausibly originated from DMAE during the reaction. The same compound was also obtained as a major product in the reaction of DMAE and meso-aryl-substituted 1,9-dibromodipyrromethene. Its unique properties, such as conformational flexibility of the bridging moiety and broad absorption in the visible region, were also revealed by 1 H NMR and UV-vis absorption spectroscopies.

scholarly journals Synthesis and characterization of π–extended “earring” subporphyrins

2018 ◽  
Vol 14 ◽  
pp. 1956-1960 ◽  
Author(s):  
Haiyan Guan ◽  
Mingbo Zhou ◽  
Bangshao Yin ◽  
Ling Xu ◽  
Jianxin Song
Keyword(s):  
Single Crystal ◽  
Aromatic Ring ◽  
Nmr Spectra ◽  
Ring Current ◽  
Synthesis And Characterization ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Single Crystal Structures

A π-extended “earring” subporphyrin 3 was synthesized from β,β′-diiodosubporphyrin and diboryltripyrrane via a Suzuki–Miyaura coupling and following oxidation. Its Pd complex 3Pd was also synthesized and both of the compounds were fully characterized by 1H NMR, MS and X-ray single crystal diffraction. The 1H NMR spectra and single crystal structures revealed that aromatic ring current did not extend to the “ear” in both of the two compounds. Their UV–vis/NIR spectra were recorded and the absorption of both compounds is extended to the NIR region and that the absorption of 3Pd is further red-shifted and more intense.

scholarly journals Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

2020 ◽  
Vol 16 ◽  
pp. 190-199
Author(s):  
Vuyisa Mzozoyana ◽  
Fanie R van Heerden ◽  
Craig Grimmer
Keyword(s):  
Single Crystal ◽  
Phenyl Ring ◽  
Fluorine Atom ◽  
Nmr Spectra ◽  
Intramolecular Interaction ◽  
X Ray ◽  
Solution State ◽  
H Nmr ◽  
Mild Conditions ◽  
C Nmr

4-(2-Fluorophenyl)-7-methoxycoumarin (6) was synthesized by Pechmann reaction under mild conditions via a three-step reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (J FH = 2.6 Hz) and 13C NMR suggested that this C–F···H–C coupling is a through-space interaction. The 2D 19F-{1H} HOESY and 1H-{19F} 1D experiments were done to confirm this F···H interaction. The single crystal X-ray structure and the DFT-optimized structure showed that the fluorinated phenyl ring favors the orientation with the fluorine atom closer to H5 than H3. The X-ray structure also showed the existence of the intermolecular C–F···H–C interaction.

scholarly journals Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C-F…H-C bond

2019 ◽  
Author(s):  
Vuyisa Mzozoyana ◽  
Fanie R van Heerden ◽  
Craig Grimmer
Keyword(s):  
Single Crystal ◽  
Phenyl Ring ◽  
Fluorine Atom ◽  
Nmr Spectra ◽  
Intramolecular Interaction ◽  
X Ray ◽  
Solution State ◽  
H Nmr ◽  
Mild Conditions ◽  
C Nmr

4-(2-fluorophenyl)-7-methoxycoumarin (6) was synthesized by Pechmann reaction under mild conditions via a three step-reaction. The solution-state 1H NMR spectra of 6 showed a strong intramolecular interaction between F and H5 (J FH = 2.6 Hz) and 13C NMR suggested that this C-F…H-C coupling is a through-space interaction. The 2‑D HOESY spectrum and 1H‑{19F} 1‑D spectrum were also done to confirm this F…H interaction. The single crystal X-ray structure and the DFT-optimized structure showed that the fluorinated phenyl ring favours the orientation with the fluorine atom is closer to H5 than H3. The X-ray structure also showed the existence of the intermolecular C-F…H-C interactions.

Structures of the 2:1 adducts of benzyne with 2-methylanisole and benzene

2007 ◽  
Vol 85 (7-8) ◽  
pp. 461-465
Author(s):  
Christopher O Bender ◽  
René T Boeré ◽  
Peter W Dibble ◽  
Ryan T McKay
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Gas Phase ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Dft Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Data Points

The 2:1 adduct of benzyne with 2-methylanisole is shown to have the bisbenzotricyclic structure 6,6a,11,11a-tetrahydro-5-methoxy-6-methyl-5,6,11-metheno-5H-benzo[a]fluorene by a single-crystal X-ray diffraction study (C20H18O: Pca21, a = 15.0497(17), b = 9.87783(11), c = 9.6846(11); Z = 4; 1672 data points, R1 = 0.0325). This structure is compared to an unpublished crystal structure of the parent hydrocarbon 6,6a,11,11a-tetrahydro-5,6,11-metheno-5H-benzo[a]fluorene, C18H14. Both structures have also been computed by DFT methods at the B3LYP/6-311(d,p) level of theory. Bond distances and angles between the solid-state measurements and gas-phase calculations are found to agree well; average deviations are well below 1%. The 1H NMR spectra show surprisingly small 3JHH couplings in the central tricyclic cage, but can be assigned using 2D spectroscopy.Key words: Hydrocarbon cages, strained rings, cyclopropane, X-ray crystallography, NMR.

Preparation, properties and structure of some intermediate nido- and arachno-monocarbaboranes

1981 ◽  
Vol 46 (10) ◽  
pp. 2345-2353 ◽  
Author(s):  
Karel Baše ◽  
Bohumil Štíbr ◽  
Jiří Dolanský ◽  
Josef Duben
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Starting Compound

The 6-N(CH3)3-6-CB9H11 carbaborane reacts with sodium in liquid ammonia with the formation of 6-CB9H12- which was used as a starting compound for preparing the 4-CB8H14, 9-L-6-CB9H13 (L = (CH3)2S, CH3CN and P(C6H5)3), 1-(η5-C5H5)-1,2-FeCB9H10-, and 2,3-(η5-C5H5)2-2,31-Co2CB9H10- carboranes. The 4-CB8H14 compound was dehydrogenated at 623 K to give 4-(7)-CB8H12 carborane. Base degradation of 6-N(CH3)3-6-CB9H11 in methanol resulted in the formation of 3,4-μ-N(CH3)3CH-B5H10. The structure of all compounds was proposed on the basis of their 11B and 1H NMR spectra and X-ray diffraction was used in the case of the transition metal complexes.

Unusual Rearrangement of Naphthalene in the Synthesis of a Novel B8-B8-Bridged Derivative in the [(1,2-C2B9H11)2-3-Co]- Series. X-Ray Structure and 11B NMR Spectra of [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- (CH3)4N+

1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unusual Rearrangement ◽  
Multinuclear Nmr Spectroscopy ◽  
11B Nmr ◽  
Isolated Compound

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.

Organometallic oxides: preparation of the cluster [(η-C5Me5)Mo]4O7 by reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O)

2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu
Keyword(s):  
Nmr Spectra ◽  
Chloroform Solution ◽  
X Ray Diffraction ◽  
Broad Resonance ◽  
Nmr Spectrum ◽  
X Ray ◽  
Temperature Range ◽  
H Nmr ◽  
Tributyltin Hydride ◽  
Effective Moment

Reduction of [(η-C5Me5)MoCl(O)]2(μ-O) or (η-C5Me5)MoCl2(O) with sodium or magnesium amalgam, magnesium turnings, or tributyltin hydride produced [(η-C5Me5)Mo]4O7, with [(η-C5Me5)Mo(O)(μ-O)]2 as a co-product. [(η-C5Me5)Mo]4O7 was characterized by X-ray diffraction, mass spectrometry, 1H NMR and IR spectroscopies, and magnetism. Crystals of [(η-C5Me5)Mo]4O7 contained a tetrahedral [(η-C5Me5)Mo]4 unit (Mo-Mo = 2.909 (3) Å) with the Mo4O7 core having the structure Mo4(μ2-O(b))3(µ2-O(c))3(µ3-O(a)) (3). Microcrystalline samples of [(η-C5Me5)Mo]4O7 were paramagnetic over the temperature range 2-300 K, with an effective moment of 1.26 μB at 300 K. [(η-C5Me5)Mo]4O7 was also paramagnetic in chloroform solution, over the temperature range 223-298 K, with an effective moment of 1.43 µB at 298 K. The 1H NMR spectrum showed a broad resonance at 16.3 ppm (Δν 1/2 = 113 Hz) and two narrow resonances at 1.89 ppm and 1.69 ppm (Δν 1/2 = 5 Hz). The magnetism and NMR spectra showed that [(η-C5Me5)Mo]4O7 existed in two forms which were in equilibrium in solution. One form was paramagnetic (S = 1), with the Mo4O7 core having the geometry 3, and the other was diamagnetic (S = 0), with the Mo4O7 core having the geometry 4.Key words: cluster, cyclopentadienyl, molybdenum, oxide, paramagnetism.

Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Komplexe / Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Complexes

2002 ◽  
Vol 57 (9) ◽  
pp. 1017-1026 ◽  
Author(s):  
Herbert Schumann ◽  
Susanne Stenz ◽  
Frank Girgsdies ◽  
Stefan H. Mühle
Keyword(s):  
Single Crystal ◽  
Nmr Spectra ◽  
X Ray ◽  
Tert Butyl ◽  
New Compounds ◽  
C Nmr

Ru3(CO)12 reacts with 1-tert-butyl-2,4-cyclopentadiene (1), 1-trimethylsilyl-2,4-cyclopentadiene (2), 1-tert-butyl-3-methyl-2,4-cyclopentadiene (3), 1,3-di(tert-butyl)-2,4-cyclopentadiene (4), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), 1-tert-butyl-2,3,4,5-tetramethyl- 2,4-cyclopentadiene (6), 1-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (7), 2,5- diphenyl-2,4-cyclopentadiene (8), or 2,3,4,5-tetraphenyl-2,4-cyclopentadiene (9) with formation of the corresponding bis[dicarbonyl(cyclopentadienyl) ruthenium(I)] complexes [RuCp# (CO)2]2 1a to 9a. The 1H and 13C NMR spectra of the new compounds 3a and 5a to 9a as well as the single crystal X-ray structures of 1a, 4a, 5a, 7a, 8a, and 9a are reported and discussed

Sign in / Sign up

Export Citation Format

Share Document