Unexpected beauty and diversity in the structures of three homologous 4,5-dialkoxy-1-ethynyl-2-nitrobenzenes: the subtle interplay between intermolecular C—H...O hydrogen bonds and alkyl chain length

2017 ◽  
Vol 73 (10) ◽  
pp. 814-819 ◽  
Author(s):  
Shalisa M. Oburn ◽  
Eric Bosch
Keyword(s):  
Nmr Spectra ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Triclinic Crystal System ◽  
Space Group ◽  
X Ray ◽  
Crystal System ◽  
C Nmr

The synthesis, 1H and 13C NMR spectra, and X-ray structures are described for three dialkoxy ethynylnitrobenzenes that differ only in the length of the alkoxy chain, namely 1-ethynyl-2-nitro-4,5-dipropoxybenzene, C14H17NO4, 1,2-dibutoxy-4-ethynyl-5-nitrobenzene, C16H21NO4, and 1-ethynyl-2-nitro-4,5-dipentoxybenzene, C18H25NO4. Despite the subtle changes in molecular structure, the crystal structures of the three compounds display great diversity. Thus, 1-ethynyl-2-nitro-4,5-dipropoxybenzene crystallizes in the trigonal crystal system in the space group R{\overline 3}, with Z = 18, 1,2-dibutoxy-4-ethynyl-5-nitrobenzene crystallizes in the monoclinic crystal system in the space group P21/c, with Z = 4, and 1-ethynyl-2-nitro-4,5-dipentoxybenzene crystallizes in the triclinic crystal system in the space group P{\overline 1}, with Z = 2. The crystal structure of 1-ethynyl-2-nitro-4,5-dipropoxybenzene is dominated by planar hexamers formed by a bifurcated alkoxy sp-C—H...O,O′ interaction, while the structure of the dibutoxy analogue is dominated by planar ribbons of molecules linked by a similar bifurcated alkoxy sp-C—H...O,O′ interaction. In contrast, the dipentoxy analogue forms ribbons of molecules alternately connected by a self-complementary sp-C—H...O2N interaction and a self-complementary sp 2-C—H...O2N interaction. Disordered solvent was included in the crystals of 1-ethynyl-2-nitro-4,5-dipropoxybenzene and its contribution was removed during refinement.

Synthesis and Structural Characterization of N,N´- Dipropyl-N,N,N´,N´-tetramethyl-1,2- ethylenediammonium Dichloride and Dibromide

2011 ◽  
Vol 66 (7) ◽  
pp. 755-758
Author(s):  
Sari M. Närhi ◽  
Janne Asikkala ◽  
Jatta Kostamo ◽  
Marja K. Lajunen ◽  
Raija Oilunkaniemi ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Water Molecules ◽  
Monoclinic Crystal System ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
Triclinic Crystal System ◽  
Space Group ◽  
X Ray ◽  
Crystal System

N,N´-Dipropyl-N,N,N´ ,N´-tetramethyl-1,2-ethylenediammonium dichloride (1) and dibromide (2) were prepared by the reaction of N,N,N´,N´-tetramethyl-1,2-ethylenediamine and the corresponding 1-halopropane. The structures of the compounds were characterized by single-crystal X-ray diffraction. 1 · 2H2O crystallizes in the triclinic crystal system, space group P1, with Z = 1, and 2 in the monoclinic crystal system, space group P21/c, with Z = 2. The crystal structures of the salts consist of discrete dications and halide anions. The packing in 1 · 2H2O consists of layers of cations with the chloride anions and water molecules forming hydrogen-bonded chains between the cation layers. In 2, the strongest H· · ·Br hydrogen bonds of 2.8138(6) and 2.8187(7) °A link the cations and anions into doublestranded chains. In both salts, cations and anions are also linked together by a further weak C-H· · ·Cl/Br hydrogen bonding network.

scholarly journals Solid state and solution structural investigation of homoleptic tin(IV) alkoxide compounds. Part I. Sn(O—t-Bu)4 and [Sn(O—i-Pr)4•HO—i-Pr]2

1991 ◽  
Vol 69 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Mark J. Hampden-Smith ◽  
Teresa A. Wark ◽  
Arnold Rheingold ◽  
John C. Huffman
Keyword(s):  
Solid State ◽  
Variable Temperature ◽  
Equilibrium Concentration ◽  
Molecular Structures ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Crystal System ◽  
Reversible Dissociation ◽  
C Nmr

The crystal and molecular structures of Sn(O—t-Bu)4• and [Sn(O—i-Pr)4•HO—i-Pr]2 have been determined by single-crystal X-ray diffraction. Sn(O—t-Bu)4 crystallizes in the monoclinic crystal system with space group C2/c, where a = 17.382(6) Å, b = 8.742(2) Å, c = 15.518(5) Å, β = 116.44(1)°, Z = 4, and R = 2.5%. Sn(O—t-Bu)4 is monomeric in the solid state, with a distorted tetrahedral tin coordination environment. [Sn(O—i-Pr)4•HO—i-Pr]2 crystallizes in the monoclinic crystal system with space group P21/n, where a = 11.808(3) Å, b = 14.356(3) Å, c = 12.380(2) Å, β = 95.27(2)°, Z = 2, and R = 4.9%. [Sn(O—i-Pr)4•HO—i-Pr]2 exhibits an edge-shared, bi-octahedral structure in the solid state that is distorted due to the presence of asymmetric hydrogen bonding between axially coordinated alcohol ligands and an isopropoxide ligand.13C NMR and IR spectroscopic data have been recorded for Sn(O—t-Bu)4 and Sn(O—t-Bu-d9)4 to establish criteria for unambiguous identification of solution structures of tin(IV) alkoxides. It is demonstrated that the two-bond [Formula: see text] coupling constant is larger for terminal alkoxide ligands than for μ2-alkoxide bridges, and the ν(Sn—O) stretching frequency has been assigned. The dynamic solution behaviour of [Sn(O—i-Pr)4•HO—i-Pr]2 has been studied using variable temperature 1H and 13C NMR spectroscopy. The data obtained are consistent with a process that involves rapid reversible dissociation of isopropanol at room temperature. Upon cooling, the equilibrium concentration of the species with coordinated alcohol increases, and the molecule undergoes rapid intramolecular proton transfer (AG≠ < 11.9 kcalmol−1). Upon further cooling, the 13C NMR data are consistent with a solution structure analogous to that found in the solid state. Key words: tin, alkoxide, NMR, dynamic, structure.

scholarly journals Synthesis And Structural Characterization Of 1-Butyl-2,3-Dimethylimidazolium Bromide And Iodide

2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  
Keyword(s):  
Unit Cell ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
X Ray ◽  
Crystal System ◽  
H Nmr ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å

Zur Darstellung und Struktur des 1.3-Dichloro-5-N.N-dimethylamino-1.3-dithia-2.4.6-triazins / Synthesis and Structure of 1,3-Dichloro-5-N,N-dimethylamino-1,3-dithia-2,4,6-triazine

1983 ◽  
Vol 38 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Herbert W. Roesky ◽  
Pierre Schäfer ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick
Keyword(s):  
Structure Analysis ◽  
Nmr Spectra ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cl Atoms ◽  
C Nmr

Abstract The six membered ring of composition (CH3)2NCN3S2Cl2 3 a was prepared from N,N-dimethylguanidinhydrochloride and trithiadiazindichloride. 3 a was characterized on the basis of mass, 1H, 13C NMR spectra and X-ray structure analysis. Crystals of 3 a are monoclinic, space group P21/c, with a = 660.3(6), b = 834.5(7), c = 1774.7(15) pm, β = 112.83(6)° and Z = 4. The C2N unit lies approximately in the plane of the [-CNSNSN-] ring, with both Cl atoms on the same side of the ring.

The chemistry of copper(I) β-diketonate compounds. Part V. Syntheses and characterization of (β-diketonate)CuLn species where L = PBu3, PPh3, and PCy3; n = 1 and 2; crystal and molecular structures of (acac)Cu(PCy3), (tfac)Cu(PCy3), (hfac)Cu(PCy3), and (hfac)Cu(PCy3)2

1992 ◽  
Vol 70 (12) ◽  
pp. 2954-2966 ◽  
Author(s):  
H.-K. Shin ◽  
M. J. Hampden-Smith ◽  
E. N. Duesler ◽  
T. T. Kodas
Keyword(s):  
Solid State ◽  
Molecular Structures ◽  
Lewis Acidity ◽  
High Yield ◽  
Monoclinic Crystal System ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Crystal System ◽  
Copper Coordination

The compounds (β-diketonate)Cu(PR3)n, where β-diketonate = 1,1,1,5,5,5-hexafluoroacetylacetonate, hfac; 1,1,1-trifluoroacetylacetonate, tfac; and acetylacetonate, acac; R = n-butyl (n-Bu), phenyl (Ph), and cyclohexyl (Cy); n = 1 and 2, have been prepared. The monotriorganophosphine adducts were prepared in high yield by the reaction of the sodium salt of the corresponding β-diketonate with [ClCu(PR3)] with elimination of sodium chloride. The bis(triorganophosphine) adducts were prepared by the reaction of (β-diketonate)Cu(PR3) with one equivalent of triorganophosphine. These species were characterized by 1H, 13C, and 31P NMR spectroscopy, FTIR spectroscopy, mass spectroscopy, and by combustion elemental analysis. Four examples were structurally characterized by single crystal X-ray diffraction in the solid state. (acac)CuPCy3 crystallizes in the triclinic crystal system, space group [Formula: see text], where a = 13.502(6) Ǻ, b = 13.691(6) Ǻ, c = 5.781(6) Ǻ, α = 71.05(3)°, β = 67.50(3)°, γ = 64.81(3)°, Z = 4, and R = 5.42%. (tfac)CuPCy3 crystallizes in the monoclinic crystal system, space group P21/n, where a = 9.639(3) Ǻ, b = 22.717(7) Ǻ, c = 12.045(5) Ǻ, β = 111.67(3)°, Z = 4, and R = 7.22%. (hfac)CuPCy3 crystallizes in the monoclinic crystal system, space group P21/c, where a = 9.870(2) Ǻ, b = 17.314(4) Ǻ, c = 15.586(3) Ǻ, β = 99.74(2)°, Z = 4, and R = 5.29%. (hfac)Cu(PCy3)2 crystallizes in the monoclinic crystal system, space group P21/n, where a = 13.645(6) Ǻ, b = 19.252(13) Ǻ, c = 16.875(9) Ǻ, β = 102.02(4)°, Z = 4, and R = 7.20%. The compounds (β-diketonate)Cu(PCy3) are all monomeric in the solid state and possess approximately trigonal-planar copper coordination environments, although (tfac)Cu(PCy3) is significantly distorted from trigonal geometry. The Cu—O bond distances are significantly different in this species. The compound (hfac)Cu(PCy3)2 is monomeric in the solid state and possesses a distorted tetrahedral copper coordination environment. The distortion is believed to be due to the large steric demands of the PCy3 ligands that result in long Cu—P bond distances of 2.251(3) and 2.277(3) Ǻ, a large P—Cu—P angle of 141.3(1)°, long Cu—O distances of 2.213(5) and 2.251(5) Ǻ, and a small O—Cu—O angle of 80.8(2)° compared to the corresponding values for (hfac)Cu(PCy3). No trends in Cu—O bond distances between the compounds can be discerned, within the limits of error on the data, that would clearly enable a comparison of thermodynamic parameters such as bond length – bond strength relationships as a function of the β-diketonate substituents. However, the spectroscopic data revealed a number of trends as a function of the β-diketonate substituents, including an increase of ν(C=O and ν(C=C) in the order acac < tfac < hfac, analogous to the increase in their Lewis acidity. An increase in shielding of the 31P resonance of the triorganophosphine ligands was observed in the order hfac < tfac < acac, consistent with expected inductive effects based on the electronegativity of the β-diketonate substituents.

Structural studies on dioxan-2-ylium ions; intramolecular attack of an oxygen atom on a carbenium ion centre

1994 ◽  
Vol 72 (10) ◽  
pp. 2084-2093 ◽  
Author(s):  
Ronald F. Childs ◽  
Guogong J. Kang ◽  
Teresa A. Wark ◽  
Christopher S. Frampton
Keyword(s):  
Carbon Chain ◽  
Intramolecular Rearrangement ◽  
Carbon Chain Length ◽  
Monoclinic Crystal ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ether Oxygen ◽  
Carbenium Ion ◽  
C Nmr

As models for the ionization of orthoesters, a series of 1,3-dioxan-2-ylium salts have been prepared and characterized. The properties of 1,3-dioxan-2-ylium hexachloroantimonate 1, 5-ethoxymethyl-1,3-dioxan-2-ylium hexachloroantimonate 2, 2-methyl-5-ethoxymethyl-1,3-dioxan-2-ylium hexachloroantimonate 3, and 2-phenyl-5-ethoxymethyl-1,3-dioxan-2-ylium hexachloroantimonate 4, have been studied by 1H and 13C NMR spectroscopy. The structures of 3 and 4 have been determined using X-ray crystallography. Salts 3 and 4 both crystallize in monoclinic crystal systems. For 3, the space group is C2/c, with a = 30.192(4) Å, b = 9.613(2) Å, c = 12.742(2) Å, β = 109.71(1)°, V = 3482(1) Å3, and Z = 8. Complex 4 crystallizes in the space group P21/n, with a = 10.638(2) Å, b = 11.849(2) Å, c = 16.970(3) Å, β = 106.84(1)°, V = 2047(1) Å3, and Z = 4. The geometries of 3 and 4 are similar with the ether oxygen disposed over the dioxan-2-ylium ring. However, the interaction between the ether oxygen and the cationic centre is not significant due to the large internuclear distance observed. The cation 5, in which the carbon chain length between the ether oxygen and C(5) was increased, was prepared. This ion was found to undergo a reversible, intramolecular rearrangement resulting in the formation of 1-methyl-4-acetoxymethyl-tetrahydrofuranyl oxonium hexachloroantimonate 11.

scholarly journals Synthesis and Catalytic Application of Two Mononuclear Complexes Bearing Diethylenetriamine Derivative Ligand

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2101
Author(s):  
Chao Liu ◽  
Zhao Yang ◽  
Hao Guo ◽  
Yu-Cai Zhao
Keyword(s):  
Catalytic Mechanism ◽  
Aromatic Aldehydes ◽  
Monoclinic Crystal System ◽  
Henry Reaction ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Crystal System ◽  
Catalytic Application ◽  
Composition And Structure ◽  
Elemental Analyses

Two mononuclear zero-dimensional Ni(II) and Zn(II) complexes bearing diethylenetriamine derivative ligand, namely [NiL(CH3COO)2(H2O)] (1) and [ZnL(CH3COO)2] (2) [L = N, N’-bis(2-hydroxybenzyl)diethylenetriamine], were synthesized under reflux conditions. The molecular composition and structure of the complexes were identified by IR, PXRD, elemental analyses, and single crystal X-ray diffraction. Complex 1 belongs to a monoclinic crystal system with the P21/n space group, and Complex 2 belongs to a monoclinic crystal system with the C2/c space group. The Henry reaction of nitromethane with aromatic aldehydes was explored with Complexes 1 and 2 as the catalyst. Results from the catalytic reaction revealed that the complexes displayed excellent catalytic activities under the optimized conditions and that the substrate scope of aromatic aldehydes could be extended to a certain extent. In addition, the possible catalytic mechanism of the Henry reaction was also deduced.

Studies of the synthesis, structure, and reduction of trans-dichloro bis(2,3-dihydro-4- and 7-methylbenzo[b]thiophene)palladium(II) complexes

1993 ◽  
Vol 71 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Peter D. Clark ◽  
Martin J. Kirk ◽  
Massood Parvez
Keyword(s):  
Single Crystal ◽  
Molecular Hydrogen ◽  
Nmr Spectra ◽  
Hydrogen Donor ◽  
Ambient Conditions ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Sulfur Containing ◽  
C Nmr

trans-Dichlorobis(2,3-dihydro-4- and -7-methylbenzo[b]thiophene)palladium(II), 1b and 1c, have been prepared by reaction of 2,3-dihydro-4- and -7-methylbenzo[b]thiophenes with palladium(II) chloride. Both 1b and 1c exhibit complex 1H and 13C NMR spectra as a result of inversion of the sulfur-containing ligands. Their structures were confirmed by single crystal X-ray studies. 1b crystallized in the triclinic space group [Formula: see text] (a = 7.219(2), b = 8.441(5), c = 8.494(7) Å, α = 61.47(5)°, β = 88.85(4)°, γ = 84.40(3)°, and R = 0.067 for 1372 observed of 1760 unique reflections). 1c also crystallized in the triclinic space group [Formula: see text] (a = 7.730(3), b = 8.056(3), c = 8.516(4) Å, α = 62.87(3)°, β = 82.31(3)°, γ = 88.82(3)°, and R = 0,040 for 1425 observed of 1825 unique reflections), 1b and 1c and the complex 1a (prepared from 2,3-dihydrobenzo[b]thiophene) were unstable in the presence of molecular hydrogen at ambient conditions, liberating the parent dihydrobenzothiophenes and forming elemental palladium. 1a was also unstable to the organic hydrogen donor tetrahydronaphthalene, again forming Pd and 2,3-dihydrobenzothiophene. Complexes 1a–c were shown to promote the shift of CO/H2O to hydrogen and CO2 although most of the hydrogen was consumed by the reduction of Pd(II) to Pd0.

6π-Tricarbonyl-Komplexe von Pyridin-Derivaten, Synthesen und Reaktionen / 6π-Tricarbonyl-Chromium Complexes of Pyridine Derivatives, Syntheses and Reactions

1984 ◽  
Vol 39 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Karl Dimroth ◽  
Rüdiger Thamm ◽  
Hans Kaletsch
Keyword(s):  
Hydrogen Atom ◽  
Phosphorus Atom ◽  
Nmr Spectra ◽  
Pyridine Derivatives ◽  
Chromium Complexes ◽  
X Ray ◽  
Chromium Hexacarbonyl ◽  
Allyl Rearrangement ◽  
Tricarbonylchromium Complexes ◽  
C Nmr

New 6π-tricarbonylchromiumpyrnftne complexes 5c and 5d could be synthesized from 2,6-di-rbutyl- and 2,4,6-tri-f-butylpyridines (3c and 3d) with chromium hexacarbonyl. They are characterized by their 1H and 13C NMR Spectra and their CO-frequencies which are rather similar to those of 6π-tricarbonylchromium-2,4 ,6-triphenyl [1] or 2,4,6-trw-butyl- [2] λ3-phosphorins. When 5d is reacted with lithiumphenyl, the phenyl residue adds to C-4, giving probably compound 7, which by methanolysis and allyl rearrangement of the hydrogen atom from position 4 to position 2 affords tricarbonylchromium-2,6-di-f-butyl-4-phenyl-1,2-dihydropyridine (8) in 56% yield. The 6π-tricarbonylchromium complexes of 2,4,6-triphenyl- or 2,4,6-tn-t-butyl-λ3-phosphorins react with lithiumorganic compounds by addition only to the phosphorus atom whose reaction with methyliodide lead to tricarbonylchromium-λ5-phosphorin-ylid complexes [2], 5 d is a well crystallized compound, the X-ray analysis of the first 6π-tricarbonylchromium pyridine derivate could be performed [3] and compared with the results of the X-ray analysis of 6π-tricarbonylchromiumx 2,4,6-triphenyl-λ3-phosphorin [4]

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

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