scholarly journals Structure and Properties of 9,14,15,16,17,18,19,20-Octahydro-9,14[1′,4′]-benzenobenzo[b]triphenylene

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Michelle E. Masnovi ◽  
John Masnovi ◽  
Steven M. Schildcrout

The compound 9,14,15,16,17,18,19,20-octahydro-9,14[1′,4′]-benzenobenzo[b]triphenylene, C28H24, was prepared by hydrogenation of the 4πs+4πs photocycloadduct of dibenz[a,c]anthracene and 1,3-cyclohexadiene with Pt/C in ethyl acetate. The X-ray diffraction analysis shows that the compound crystallizes in the monoclinic space group P21/c with the geometric parameters of a = 11.0090(17) Å, b = 13.733(2) Å, c = 13.091(2) Å, and β = 109.583(13)°. In addition to several close intramolecular contacts involving hydrogens derived from the dibenzanthracene moiety, long interannular C–C single bonds of about 1.593 Å are present. These bonds are shorter by about 0.18 Å than the corresponding bonds in the unsaturated precursor, which can be attributed to reduced strain in the more saturated polycyclic ring system. Anisotropic shielding of the four endo-methylene hydrogens in the 1H NMR spectrum is larger for the two hydrogens lying above the phenanthrene unit, which resonate at 1.03 ppm, than those above the benzenoid ring, which resonate at 1.24 ppm. Theoretical calculations reproduce the geometry with good agreement.

1995 ◽  
Vol 50 (7) ◽  
pp. 1025-1029 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.


2000 ◽  
Vol 78 (3) ◽  
pp. 383-394
Author(s):  
Frank Bottomley ◽  
Victor Sanchez ◽  
Robert C Thompson ◽  
Olusola O Womiloju ◽  
Zhiqiang Xu

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.


2021 ◽  
Author(s):  
Adedibu Clement Tella ◽  
Samson Owalude ◽  
Vincent Adimula ◽  
Adetola Oladipo ◽  
Victoria Olayemi ◽  
...  

Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.


2000 ◽  
Vol 55 (5) ◽  
pp. 373-376 ◽  
Author(s):  
Andrey B. Lysenko ◽  
Oleg V. Shishkin ◽  
Rostislav D. Lampeka

The 1:1 complex of palladium(II) chloride with 2-(2-methyl-3-phenyl-isoxazolidin-5-yl)- pyridine (L) has been prepared and studied by means of elemental analysis, 1H NMR spectroscopy and X-ray diffraction (monoclinic, space group P21/n with parameters: a = 8.141(2), b = 9.750(2),c = 20.691(6)Å ,β = 95.62(3)°,V = 1634.4(7)Å3 ,Z = 4 ;R1= 0.054 and wR2= 0.144 for 3352 unique reflections). A square-planar coordination polyhedron has been established for the palladium atom both in acetone solution and in the solid state. The organic ligand is coordinated toometal in a bidentate manner via nitrogen atoms of the pyridine substituent (Pd-N(2) 2.125(3) Å) and the isoxazolidine heterocycle (Pd-N(l) 2.102(3) Å). The other two coordination positions of palladium are occupied by chlorine atoms (Pd-Cl(l) 2.321(1) and Pd-Cl(2) 2.333(1) Å). The six-membered chelate ring formed by Pd, N(2), C(4), C(1), 0(1) and N (1) possesses a “twist-tub” conformation. The isoxazolidine cycle has an envelope conformation with an equatorial orientation of the methyl group.


2016 ◽  
Vol 20 (08n11) ◽  
pp. 997-1001 ◽  
Author(s):  
Koji Naoda ◽  
Atsuhiro Osuka

Triphenylphosphine was added regioselectively at the C(3) position of bis-Au(III) complex of [26]hexaphyrin 5 in the presence of trifluoroacetic acid to produce [28]hexaphyrin triphenylphosphine adduct 6 in 62% yield, which has been fully characterized by NMR, UV-vis/NIR absorption, and MS spectroscopies, and X-ray diffraction analysis. The rigid planar structure forces 6 to take Hückel antiaromaticity, which has been supported by its 1H NMR spectrum. Curiously, the detailed structural analysis elucidated that the triphenylphosphine moiety exists as a phosphorane form in the solid state. A plausible mechanism via a double protonated 5 is proposed, which can explain the observed regioselectivity.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tetsuji Moriguchi ◽  
Tatsuya Egami ◽  
Akihiko Tsuge

A large calixarene-like metacyclophane, 4′,9′,4″,9″-tetra-tert-butyl-1′,6′,1″,6″-tetramethoxy-2,5-dioxa[3.3]metabiphenylophane, was synthesized by an intermolecular condensation reaction of its corresponding bischloromethyl-biphenyl and bishydroxymethyl-biphenyl precursors. After molecular characterization by 1H NMR spectroscopy and mass spectrometry, the compound generated single crystals by recrystallization from a dichloromethane/hexane mixture, facilitating an exact conformational determination via X-ray diffraction analysis. The crystal was found to belong to the monoclinic space group P21/n with cell parameters a = 19.908(2) Å, b = 9.7193(11) Å, c = 23.350(3) Å, β = 109.594(1)°, and Dcalc=1.150 g/cm3 at 90 K. The compound adopted quite strained 1,2-alternate-like conformations because its biphenyl parts displayed large dihedral angles and rigidity. The crystal did not incorporate any solvent molecule but its molecular cavity and crystal space were effectively filled by the substituents.


1996 ◽  
Vol 51 (5) ◽  
pp. 744-746 ◽  
Author(s):  
A. Franken ◽  
H. Thomsen ◽  
W. P reetz

By reaction of conjuncto-[B6H6-B6H6]2- in alkaline solution with excess bromine the heptabromo-closo-heptaborate, [B7Br7]2 is formed. The crystal structure of [(CsH3N)2CH2][B7Br7] has been determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/a with a = 15.0843(14), b = 9.8882(14), c = 17.057(2) Å, β = 114.039°(7)). In accordance with the D5h point symmetry, the anion shows two singlets at -23.3 and -0.1 ppm with the intensity ratio 2:5 in its 11B NMR spectrum.


1983 ◽  
Vol 38 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Bernt Krebs ◽  
Marita Hucke ◽  
Michael Hein ◽  
Andreas Schäffer

Abstract The monomeric SeOCl3- ion, which can be prepared as the tetraphenylarsonium salt from SeOCl2 and As(C6H5)4Cl, was structurally characterized by a low-temperature single crystal X-ray diffraction analysis. [As(C6H5)4]SeOCl3 is monoclinic, space group P21/c, with a = 9,332(3), b = 13,761(4), c = 18,985(6) Å, β = 110,97(3)° (at -135 °C), Z = 4; it contains a novel type of ψ-trigonal bipyramidal oxotrichloroselenate(IV) anion which is not associated to dimers or polymer chains as in known structures. The equatorial positions are occupied by doubly bonded oxygen (Se-O 1,601(3) Å) and by one Cl(Se-Cl 2,234(1) Å), the axial Se-Cl bonds (2,430(1) and 2,475(1) Å) being significantly longer. [N(C2H5)4]SeOCl3, which was obtained as crystals by oxidation of trichloroselenate(II), is triclinic, space group P1̄, with a = 10,607(3), b = 8,950(2), c = 8,862(2) Å, α = 119,79(2)°, β = 101,07(2)°, γ = 96,28(2)°, Z = 2. The X-ray structure analysis shows the anions to be present as centrosymmetric dimers Se2O2Cl62- like in the [P(C6H5)4]+ salt, with two tetragonal SeOCl4 pyramids linked through a Cl···Cl edge and the lone pairs trans to the axial Se-O bonds (1,589(4) Å). Se-Cl bond lengths are 2.270(1) and 2,351(2) Å (terminal); 2,698(1) and 2,920(1) Å (bridging). The results show that the nature of the reaction products of the Lewis acid SeOCl2 with halogenides as bases changes very sensitively with small variations in cations and environment. The vibrational spectra are discussed.


2015 ◽  
Vol 70 (10) ◽  
pp. 719-725 ◽  
Author(s):  
Cristian Villa-Pérez ◽  
Isabel C. Ortega ◽  
Angélica M. Payán-Aristizábal ◽  
Gustavo Echeverría ◽  
Gloria C. Valencia-Uribe ◽  
...  

AbstractA new complex of Hg(II) with 6-methoxyquinoline (C10H9NO-6MQ) has been synthesized and characterized. The structure of the complex Hg(6MQ)Cl2 was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c with a = 3.9139(3), b = 26.3400(2), c = 10.9090(9) Å, β = 89.833(6)°, V = 1124.6(1) Å3 and Z = 4 molecules per unit cell. The coordination geometry of the mercury(II) center can be described as a distorted square pyramid formed by one nitrogen atom of the 6MQ and four chlorine atoms. Fourier transform infrared, Raman and UV/Vis spectroscopic studies have been carried out to characterize the compound, using theoretical calculations for the assignment of the experimentally observed bands. The thermal behavior was investigated by thermogravimetric analysis. The quantum yield of singlet molecular oxygen production ΦΔ was measured with steady-state methods in ethanol, using 9,10-dimethylanthracene (DMA) as actinometer and Bengal rose as reference photosensitizer. The resultant singlet molecular oxygen was detected indirectly by photooxidation reactions of DMA. The luminescence properties have also been studied.


1995 ◽  
Vol 50 (1) ◽  
pp. 11-14 ◽  
Author(s):  
A. Franken ◽  
W. Preetz

Aminohexahydro-closo-hexaborate(1–), Crystal Structure, 11B NMR Spectra, Vibrational SpectraBy reduction of [B6H5(NO2)]2- with Fe2+ in aqueous alkaline solution [B6H6(NH2)]- is formed. The compound has been separated by extraction with dichloromethane in the presence of tetrabutylammoniumbromid and precipitated from the organic phase by adding CsCH3COO/C2H5OH. The Crystal structure of Cs[B6H6(NH2)] · H2O has been determined by single crystal X-ray diffraction analysis; monoclinic space group C2 with a = 22.1075(14), b = 6.491(2), c = 5.9570(4) A, β = 100.168(6)°. The 11B NMR spectrum is consistent with a mono-hetero-substituted octahedral B6 cage with local C4v symmetry. The IR and Raman spectra exhibit characteristic N–H, B–H and B6 vibrations.


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