scholarly journals Molecular structures of the pentaphenylcyclopentadienyl iron complexes [(C5Ph5)Fe(CO)2 R] (R = Me, Ph, iPr and Bu)

2021 ◽  
Vol 77 (7) ◽  
Author(s):  
Karlheinz Sünkel ◽  
Christian Klein-Hessling
Keyword(s):  
Crystal Structure ◽  
Iron Complexes ◽  
Molecular Structures ◽  
Electronic Effects ◽  
Alkyl Aryl ◽  
Butyl Lithium ◽  
Catalysed Reaction ◽  
Structure Determinations ◽  
Aryl Complexes ◽  
Phenyl Rings

The PdII-catalysed reaction of [(C5Ph5)Fe(CO)2Br] with Grignard compounds RMgX or butyl lithium gave the iron alkyl/aryl complexes [(C5Ph5)Fe(CO)2 R] (R = Me, Ph, iPr and Bu) in 59–73% yield, namely, dicarbonylmethyl(η5-pentaphenylcyclopentadienyl)iron, [Fe(CH3)(C35H25)(CO)2], dicarbonyl(η5-pentaphenylcyclopentadienyl)phenyliron, [Fe(C6H5)(C35H25)(CO)2], dicarbonyl(isopropyl)(η5-pentaphenylcyclopentadienyl)iron, [Fe(C3H7)(C35H25)(CO)2], and butyldicarbonyl(η5-pentaphenylcyclopentadienyl)iron, [Fe(C4H9)(C35H25)(CO)2]. The crystal structure determinations showed the usual `paddle-wheel' orientation of the phenyl rings, with an average canting angle of ca 50°. The bond parameters are mainly dictated by the steric requirements of the alkyl/aryl groups and only the phenyl complex shows electronic effects.

Arsenic(III), Antimony (III) and Bismuth(III) Thiobenzoates: Crystal and Molecular Structures of M(SOCR)3 and PhSb(SOCPh)2

1998 ◽  
Vol 53 (12) ◽  
pp. 1475-1482 ◽  
Author(s):  
Prit Singh ◽  
Sudha Singh ◽  
Vishnu D. Gupta ◽  
Heinrich Nöth
Keyword(s):  
Crystal Structure ◽  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Covalently Bonded ◽  
Bismuth Complex ◽  
Group 15 ◽  
Structure Determinations ◽  
Trigonal Pyramid ◽  
Trigonal Prisms

Abstract Tris-thiobenzoates, Arsenic, Antimony, Bismuth Tris-thiobenzoates of arsenic, antimony and bismuth, M(SOCR)3 have been obtained from their oxides and characterized. In the X-ray crystal structure determinations of these, the group 15 atom and the three covalently bonded sulfur atoms are found to constitute a trigonal pyramid, the central atoms lie at a C3 axis. In the bismuth complex the thiobenzoate ligand tends to chelate. However, three comparatively short intermolecular M···S interactions are significant features for these molecules resulting in stacking of trigonal prisms providing an essentially six coordinate environment around arsenic and antimony and a nine-coordinate one for bismuth. The structure of PhSb(SOCPh)2 can be considered

Conformational studies on heteroleptic trifluoromethyl-substituted phenylboranes

2016 ◽  
Vol 72 (3) ◽  
pp. 189-197 ◽  
Author(s):  
Kamil Samigullin ◽  
Yashar Soltani ◽  
Hans-Wolfram Lerner ◽  
Matthias Wagner ◽  
Michael Bolte
Keyword(s):  
Phenyl Ring ◽  
Lewis Acids ◽  
Geometric Parameters ◽  
Molecular Structures ◽  
Electronic Effects ◽  
Frustrated Lewis Pairs ◽  
Acidic Catalysts ◽  
Phenyl Rings ◽  
Trifluoromethyl Groups ◽  
Lewis Acids And Bases

Organoboranes carrying electron-withdrawing substituents are commonly used as Lewis acidic catalysts or cocatalysts in a variety of organic processes. These Lewis acids also became popular through their application in `frustrated Lewis pairs',i.e.combinations of Lewis acids and bases that are unable to fully neutralize each other due to steric or electronic effects. We have determined the crystal and molecular structures of four heteroleptic arylboranes carrying 2-(trifluoromethyl)phenyl, 2,6-bis(trifluoromethyl)phenyl, 3,5-bis(trifluoromethyl)phenyl or mesityl substituents. [3,5-Bis(trifluoromethyl)phenyl]bis[2-(trifluoromethyl)phenyl]borane, C22H11BF12, (I), crystallizes with two molecules in the asymmetric unit which show very similar geometric parameters. In one of the two molecules, both trifluoromethyl groups of the 3,5-bis(trifluoromethyl)phenyl substituent are disordered over two positions. In [3,5-bis(trifluoromethyl)phenyl]bis[2,6-bis(trifluoromethyl)phenyl]borane, C24H9BF18, (II), only one of the twometa-trifluoromethyl groups is disordered. In [2,6-bis(trifluoromethyl)phenyl]bis[3,5-bis(trifluoromethyl)phenyl]borane, C24H9BF18, (III), bothmeta-trifluoromethyl groups of only one 3,5-bis(trifluoromethyl)phenyl ring are disordered. [3,5-Bis(trifluoromethyl)phenyl]dimesitylborane, C26H25BF6, (IV), carries only onemeta-trifluoromethyl-substituted phenyl ring, with one of the two trifluoromethyl groups disordered over two positions. In addition to compounds (I)–(IV), the structure of bis[2,6-bis(trifluoromethyl)phenyl]fluoroborane, C16H6BF13, (V), is presented. None of theortho-trifluoromethyl groups is disordered in any of the five compounds. In all the structures, the boron centre is in a trigonal planar coordination. Nevertheless, the bond angles around this atom vary according to the bulkiness and mutual repulsion of the substituents of the phenyl rings. Also, theortho-trifluoromethyl-substituted phenyl rings usually show longer B—C bonds and tend to be tilted out of the BC3plane by a higher degree than the phenyl rings carryingorthoH atoms. A comparison with related structures corroborates the conclusions regarding the geometric parameters of the boron centre drawn from the five structures in this paper. On the other hand, CF3groups inmetapositions do not seem to have a marked effect on the geometry involving the boron centre. Furthermore, it has been observed for the structures reported here and those reported previously that for CF3groups inorthopositions of the aromatic ring, disorder of the F atoms is less probable than for CF3groups inmetaorparapositions of the ring.

scholarly journals Crystal and molecular structures of some phosphane-substituted cymantrenes [(C5H4 X)Mn(CO)LL′] (X = H or Cl, L = CO, L′ = PPh3 or PCy3, and LL' = Ph2PCH2CH2PPh2)

2021 ◽  
Vol 77 (10) ◽  
Author(s):  
Karlheinz Sünkel ◽  
Christian Klein-Hessling
Keyword(s):  
Crystal Structure ◽  
Uv Irradiation ◽  
Molecular Structures ◽  
Bond Lengths ◽  
Crystal And Molecular Structures ◽  
Chlorine Substitution ◽  
Small Influence ◽  
Intermolecular Association ◽  
Structure Determinations

UV irradiation of tetrahydrofuran solutions of [CpMn(CO)3] (Cp = π-C5H5 or π-C5H4Cl) in the presence of the phosphanes PPh3 or PCy3 (Cy = cyclohexyl) and Ph2PCH2CH2PPh2 yields the substitution products [CpMn(CO)2PR 3] (R = Ph or Cy) and [CpMn(CO)(Ph2PCH2CH2PPh2)], namely, dicarbonyl(η5-cyclopentadienyl)(triphenylphosphane-κP)manganese(I), [Mn(C5H5)(C18H15P)(CO)2], 1a, dicarbonyl(η5-1-chlorocyclopentadienyl)(triphenylphosphane-κP)manganese(I), [Mn(C5H4Cl)(C18H15P)(CO)2], 1b, dicarbonyl(η5-cyclopentadienyl)(tricyclohexylphosphane-κP)manganese(I), [Mn(C5H5)(C18H33P)(CO)2], 2a, dicarbonyl(η5-1-chlorocyclopentadienyl)(tricyclohexylphosphane-κP)manganese(I), [Mn(C5H4Cl)(C18H33P)(CO)2], 2b, carbonyl(η5-cyclopentadienyl)[1,2-bis(diphenylphosphanyl)ethane-κ2 P,P′]manganese(I), [Mn(C5H5)(C26H24P2)(CO)], 3a, and carbonyl(η5-1-chlorocyclopentadienyl)[1,2-bis(diphenylphosphanyl)ethane-κ2 P,P′]manganese(I), [Mn(C5H4Cl)(C26H24P2)(CO)], 3b, The crystal structure determinations show a very small influence of the chlorine substitution and a moderate influence of the phosphane substitution on the bond lengths. The PR 3 groups avoid being eclipsed with the C—Cl bonds. All the compounds employ weak C—H...O interactions for intermolecular association, which are enhanced by C—H...Cl contacts in the chlorinated products.

Indium Triiodide Complexes of Bis(diphenyIphosphino)ethane (dppe) and its Disulfide (dppeS2)

1999 ◽  
Vol 54 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Marcus Sigl ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Crystal Structure ◽  
Ionic Species ◽  
Molecular Structures ◽  
Trans Conformation ◽  
Structure Determinations ◽  
Terminal Complexes ◽  
High Yields

Bis(diphenylphosphino)ethane (dppe) and its disulfide (dppeS2) react with two equivalents of indium triiodide to give high yields of the corresponding 1:2 adducts. According to crystal structure determinations, both compounds are molecular bis-terminal complexes with the ligands in an all-trans conformation. Contrary to previous findings for complexes of the indium trihalides and of GaBr3 and Gal3 with ditertiary phosphines in fixed cis-structure [bis(diphenylphosphino)ethene or -benzene], no iodide redistribution is observed to give the ionic species [(dppe)Inl2]+ [InI4 ]- . The molecular structures are also retained in solution.

Synthese und Kristallstrukturen der Wolfram(VI)-Alkinkomplexe [WCl4(Ph - C≡C - I)(THF)] und [WCl4(Ph-C≡C-Te-C4H9)(THF)] / Synthesis and Crystal Structures of the Tungsten(VI) Alkyne Complexes [WCl4(Ph-C≡C-I)(THF)] and [WCl4(Ph-C≡C-Te-C4H9)(THF)]

1993 ◽  
Vol 48 (8) ◽  
pp. 1105-1111 ◽  
Author(s):  
Michael Plate ◽  
Peter Hofacker ◽  
Werner Massa ◽  
Birgit Schwarz ◽  
Bernhard Neumüller ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Oxygen Atom ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Trans Position ◽  
Space Group ◽  
Structure Determinations ◽  
In Trans ◽  
Alkyne Complexes

[WCl4(Ph-C≡C-I)(THF)] has been prepared by the reaction of trans-[WCl4(SEt2)2] with Ph - C≡C - I in THF solution, whereas [WCl4(Ph-C≡C-Te-nC4H9)(THF)] has been synthesized by the reaction of Ph-C≡C-Te-nC4H9 with tungsten hexacloride in the presence of C2Cl4 and THF. Both complexes were characterized by IR spectroscopy and by crystal structure determinations.[WCl4(Ph-C≡C-I)(THF)]: Space group P21/c, Z = 4, 2617 observed unique reflections, R = 0.064. Lattice dimensions at –70°C: a = 1518.2(3), b = 714.5(1), c = 1540.0(3) pm, β = 90.09(3)°.[WCl4(Ph-C≡C-Te–nC4H9)(THF)]. Space group P1̄, Z = 2, 3911 observed unique reflections, R = 0.067. Lattice dimensions at 20°C: a = 844.0(3), b = 974.6(4), c = 1002.4(3) pm, α = 76.00(4), β= 105.14(1), γ = 82.03(3)°.Both complexes have molecular structures, in which the tungsten atoms are seven-coordi-nate by four chlorine ligands, by the two alkyne carbon atoms, and in trans position to the latter by the oxygen atom of the THF molecule. The WC bond lengths are 198 and 200(1) in the telluro complex and 206 and 196(1) pm in the iodine derivative.

Ringkontraktion am Cyclotrisilazan -System - Synthese und Molekülstrukturen zweifach silylverknüpfter Cyclodisilazane / Ring Contraction in the Cyclotrisilazane System - Synthesis and Molecular Structures of Silyl-Bridged Cyclodisilazanes

1980 ◽  
Vol 35 (11) ◽  
pp. 1359-1365 ◽  
Author(s):  
William Clegg ◽  
Michael Hesse ◽  
Uwe Klingebiel ◽  
George M. Sheldrick ◽  
Lutz Skoda
Keyword(s):  
Crystal Structure ◽  
Molecular Structures ◽  
Lithium Salts ◽  
Ring Contraction ◽  
System Synthesis ◽  
Structure Determinations

Abstract l-(Fluorodiorganylsilyl)-2,2,4,4,6,6-hexamethyl-3-(trimethylsilyl)cyclotrisilazanes react with butyllithium to give the corresponding lithium salts. Ring contraction of the lithium salts with formation of lithiated (fluorodiorganylsilyl)amino-substituted four-membered rings is observed in THF solution. The dimerisation of these cyclodisilazanes with elimination of LiF is demonstrated by crystal structure determinations of three products. Monoclinic and triclinic crystalline modifications of one compound could be isolated.

Beiträge zur Chemie des 4,5-Benzo-3-methyl-1,3,2-oxazaphosphorinan- 6-on Ringsystems: Röntgenstrukturanalysen an einem Bis(2-chlorethyl)amino- und einem Acetamido-substituierten Derivat / Chemistry of the 4,5-Benzo-3-methyl-1,3,2-oxazaphosphorinan-6-one Ring System: X-Ray Crystal Structure Analysis of a Bis(2-chloroethyl)amino- and of an Acetamido-Substituted Derivative

1994 ◽  
Vol 49 (7) ◽  
pp. 939-949 ◽  
Author(s):  
Axel Fischer ◽  
Ion Neda ◽  
Thomas Kaukorat ◽  
Ralf Sonnenburg ◽  
Peter G. Jones ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Peroxide ◽  
Elemental Sulfur ◽  
Crystal Structure Analysis ◽  
Ring System ◽  
Molecular Structures ◽  
X Ray ◽  
Spectrometric Data ◽  
Structure Determinations ◽  
Phosphoryl Compound

Abstract The reaction of 4,5-benzo-2-chloro-3-methyl-1,3,2-oxazaphosphorinan-6-one 1 with 1,2-bis- (trimethylsiloxy)ethane led to the bisphosphoryl species 2a and to the isomeric bisphosphite derivative 2b. The reaction of 1 with heptamethyldisilazane furnished the expected diphos­phorus compound 3, with two λ3P(III) atoms linked by a methylamino group. Substitution of the chlorine atom of 1 by the 2-chloroethylamino and bis(2-chloroethyl)amino group led to the oxazaphosphorinanones 4 and 6. By oxidation of 4 with the hydrogen peroxide/urea 1:1-adduct, the phosphoryl compound 5 was formed. Oxidation of 4,5-benzo-2-diethyl- amino-3-methyl-1,3,2-oxazaphosphorinan-6-one 7 [1] with hydrogen peroxide, sulfur and se­lenium led to the corresponding phosphoryl, thiophosphoryl and selenophosphoryl com­pounds 8-10. Analogously, the reaction of the dimethylamino- and acetamido-substituted derivatives 11 and 13 [1] with elemental sulfur furnished the thiophosphoryl compounds 12 and 14. X-ray crystal structure determinations of 4 and 14 confirmed the molecular structures, proposed in accord with NMR spectroscopic and mass spectrometric data. The heterocyclic rings are essentially planar. In 14 a hydrogen bond N-H···O (amide) is observed.

Single-crystal X-ray structure determinations of vardenafil, vardenafil dihydrate, vardenafil monohydrochloride trihydrate and vardenafil dihydrochloride hexahydrate

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dedong Wu ◽  
Faraj Atassi
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Single Crystal ◽  
Molecular Structures ◽  
Free Base ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Structure Determinations ◽  
Good Agreement

AbstractThe crystal and molecular structures of vardenafil (free, unprotonated base), vardenafil dihydrate and the hydrochloride salts, vardenafil monohydrochloride trihydrate and vardenafil dihydrochloride hexahydrate, were determined by single-crystal X-ray diffraction. The crystal structure of vardenafil monohydrochloride trihydrate is in good agreement with the published crystal structure obtained by powder diffraction using synchrotron radiation. This work shows that the crystal structure of anhydrous vardenafil free base is very similar to the crystal structure of sildenafil free base.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Resolving Entangled JH-H-Coupling Patterns for Steroidal Structure Determinations by NMR Spectroscopy

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2643
Author(s):  
Danni Wu ◽  
Kathleen Joyce Carillo ◽  
Jiun-Jie Shie ◽  
Steve S.-F. Yu ◽  
Der-Lii M. Tzou
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Atomic Level ◽  
Molecular Structures ◽  
Naturally Occurring ◽  
Structure Determinations ◽  
Ligand Interactions ◽  
Synthetic Steroids ◽  
The Individual

For decades, high-resolution 1H NMR spectroscopy has been routinely utilized to analyze both naturally occurring steroid hormones and synthetic steroids, which play important roles in regulating physiological functions in humans. Because the 1H signals are inevitably superimposed and entangled with various JH–H splitting patterns, such that the individual 1H chemical shift and associated JH–H coupling identities are hardly resolved. Given this, applications of thess information for elucidating steroidal molecular structures and steroid/ligand interactions at the atomic level were largely restricted. To overcome, we devoted to unraveling the entangled JH–H splitting patterns of two similar steroidal compounds having fully unsaturated protons, i.e., androstanolone and epiandrosterone (denoted as 1 and 2, respectively), in which only hydroxyl and ketone substituents attached to C3 and C17 were interchanged. Here we demonstrated that the JH–H values deduced from 1 and 2 are universal and applicable to other steroids, such as testosterone, 3β, 21-dihydroxygregna-5-en-20-one, prednisolone, and estradiol. On the other hand, the 1H chemical shifts may deviate substantially from sample to sample. In this communication, we propose a simple but novel scheme for resolving the complicate JH–H splitting patterns and 1H chemical shifts, aiming for steroidal structure determinations.

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