1,3-Distanna-2-phospha-[3]ferrocenophanes - Synthesis, Reactivity and NMR Spectroscopic Properties

1999 ◽  
Vol 54 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Max Herberhold ◽  
Udo Steffl ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Dynamic Process ◽  
Phosphorus Atom ◽  
Spectroscopic Properties ◽  
Coupling Constants ◽  
Nmr Data ◽  
Fast Movement ◽  
New Compounds

1,1,3,3-Tetramethyl-2-organo(R)-1,3-distanna-2-phospha-[3]ferrocenophanes [R = Me (2a), tBu (2b), C6H11 (2c), Ph (2d)] and one arsa-analogue 2d(As) were obtained from the reaction of 1,1′-bis(chlorodimethylstannyl)ferrocene 1 with either bis(trimethylsilyl)methylphosphane or the dilithio derivatives, Li2PR and Li2AsPh, respectively. All compounds 2 react with chalcogens (oxygen, sulfur, selenium) by cleavage of the Sn-P bonds and formation of the known 1,3-distanna-2-chalcogena-[3]ferrocenophanes. In contrast, 2d traps pentacarbonylmetal fragments [M(CO)5] to give the stable phosphane complexes [M = Cr (4d), Mo (5d), W (6d)]. The 1,1′-bis(diorganophosphanostannyl)ferrocenes [R = tBu (3b), Ph (3d)] were prepared for comparison of NMR data. The ferrocenophanes 2 are fluxional with respect to fast movement of the cyclopentadienyl rings which induces inversion at the pyramidal phosphorus atom. This dynamic process is slow in the cases of 2d(As) and of the pentacarbonyl complexes 4d - 6d. All new compounds were characterised by 1H, 13C, 31P and 119Sn NMR spectroscopy. Various 2D heteronuclear shift correlations (e.g. 31P/1H and 119Sn/1H ) were carried out for the compounds 2 and also for non-cyclic derivatives such as bis(trimethylstannyl)phenvlphosphane and -arsane in order to determine absolute signs of coupling constants [e.g. 1J(119Sn,31P) > 0 and 2J(119Sn,117Sn) < 0]. The NMR data suggest that the molecular frameworks of the ferrocenophanes 2 are not particularly strained.

Unexpected Keto-enol Tautomerism in the Cyclopyridinophane Class Direct and indirect proofs

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Paul Ionut Dron ◽  
Neculai Doru Miron ◽  
Gheorghe Surpateanu
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Stable Conformer ◽  
Ph Measurements ◽  
Theoretical Methods ◽  
Nmr Data ◽  
Tautomeric Forms ◽  
New Compounds

The paper presents the synthesis of cyclo (bis-paraquat p-phenylene p-phenylene-carbonyl) tetrakis (hexafluorophosphate), named �CETOBOX�, and the closely related structural determinations. This compound exists in three tautomeric forms. These forms were evidentiated by NMR-data (1H-NMR, TOCSY, COSY, NOESY), UV-Vis spectra coupled with pH measurements and by synthesis. As the �CETOBOX� gives �in situ� only the corresponding monoylide, the synthesis of a new fluorescent indolizine cyclophane has been performed by a 3+2 cycloaddition. All structures of the new compounds presented herein have been established by NMR spectroscopy. Also, theoretical methods (MM3, AM1, AM1-COSMO and B88LYPDFT) have been used to determine the most stable conformer structures.

Hexaethyl-2,4-dicarba-nido-hexaborane(8), Deprotonation and Complexation Studied by NMR Spectroscopy and Density Functional Theory (DFT) Calculations

2004 ◽  
Vol 59 (6) ◽  
pp. 685-691 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Analogous Reaction ◽  
Sandwich Complex ◽  
Dft Methods ◽  
Functional Theory ◽  
Nmr Data

Deprotonation of hexaethyl-2,4-dicarba-nido-borane(8) 2 leads first to the hexaethyl-2,4-dicarbanido- borate(1−) 3, and further deprotonation, using BuLi/KOtBu, gives the hexaethyl-2,4-dicarbanido- hexaborate(2−) 4. The reaction of 3 with FeCl2 affords the commo-ferracarborane [Fe(Et6-2,4- C2B4H)2] 5, and the analogous reaction of 4 leads to the anionic sandwich complex [Fe(Et6-2,4- C2B4)2]2− 6 which can be protonated to give 5. The complex 5 contains two hydrido ligands, each bridging the iron and two boron atoms. Reactions were monitored and the products were characterised by 11B NMR spectroscopy in solution. The geometries of the carboranes, the borates (all unsubstituted and permethyl-substituted) and the iron complexes (all unsubstituted) were optimised by DFT methods [B3LYP/6-311+G(d,p) or B3LYP/6-31+G(d)], and the relevant NMR data [chemical shifts δ11B, δ13C, δ57Fe, and coupling constants 1J(13C,1H), 1J(11B,1H), 1J(57Fe,1H), 1J(57Fe,11B)] were calculated at the same level of theory.

Tri(Terf-Butyl)plumbyl-phosphanes, Synthesis and Multinuclear Magnetic Resonance

2000 ◽  
Vol 55 (10) ◽  
pp. 939-945 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Volker Tröbs ◽  
Bernd Wrackmeyer
Keyword(s):  
Magnetic Resonance ◽  
Phosphorus Atom ◽  
Coupling Constants ◽  
Tert Butyl ◽  
Nmr Data ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Multinuclear Magnetic Resonance

AbstractThe reaction of tri(tert-butyl)plumbyl-lithium (1) with various phosphorus chlorides was studied. With diphenyl- and amino(phenyl)phosphorus chlorides the formation of hexa(tertbutyl) diplumbane (2) and tetraphenyldiphosphane (3) or the respective 1,2-bis(am ino)-1,2-diphenyl- diphosphanes [e. g. 5: amino = PhCH2(tBu)N] was dominant. The presence of at least one tert-butyl group at the phosphorus atom gave access to tri(tert-butyl)plumbyl-di(tert-butyl) phosphane (4) and to tri(tert-butyl)plumbyl-amino(tert-butyl)phosphanes [amino = tBu(H)N (6), Me(Ph)N (7), PhCH2(Me)N (8), PhCH2(tBu)N (9)] via the reaction of 1 with the corresponding phosphorus chlorides. Side products were again 2 and the corresponding diphosphanes, unidentified compounds, and in two cases, bis(phosphanyl)-di(tert-butyl)plumbanes [phosphanyl = tBu(H)N(tBu)P (10), Me(Ph)N(tBu)P (11)]. Trimethylplumbyl-benzyl(methyl)- amino(tert-butyl)phosphane (12) was prepared for comparison. All compounds were characterized by their 1H , 13C, 15N (9 ),31P and 207Pb NMR data. The coupling constants 1J(207Pb,31P) are large and negative, whereas the coupling constants 1J(207Pb, 13C) are small and can be of either sign. The coupling constants 2J(31P-N-13C) of 6 - 12 indicate a preferred conformation of the substituents at phosphorus and nitrogen

Diminished electron density in the Vaska-type rhodium(I) complextrans-[Rh(NCBH3)(CO)(PPh3)2]

2016 ◽  
Vol 72 (7) ◽  
pp. 514-517
Author(s):  
M. R. Galding ◽  
A. V. Virovets ◽  
I. V. Kazakov ◽  
M. Scheer ◽  
S. N. Smirnov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nmr Spectroscopy ◽  
Electron Density ◽  
Coupling Constants ◽  
X Ray Diffraction ◽  
Metathesis Reaction ◽  
Carbonyl Carbon ◽  
Carbonyl Ligand ◽  
X Ray ◽  
Nmr Data

Vaska-type complexes,i.e. trans-[RhX(CO)(PPh3)2] (Xis a halogen or pseudohalogen), undergo a range of reactions and exhibit considerable catalytic activity. The electron density on the RhIatom in these complexes plays an important role in their reactivity. Many cyanotrihydridoborate (BH3CN−) complexes of Group 6–8 transition metals have been synthesized and structurally characterized, an exception being the rhodium(I) complex. Carbonyl(cyanotrihydridoborato-κN)bis(triphenylphosphine-κP)rhodium(I), [Rh(NCBH3)(CO)(C18H15P)2], was prepared by the metathesis reaction of sodium cyanotrihydridoborate withtrans-[RhCl(CO)(PPh3)2], and was characterized by single-crystal X-ray diffraction analysis and IR,1H,13C and11B NMR spectroscopy. The X-ray diffraction data indicate that the cyanotrihydridoborate ligand coordinates to the RhIatom through the N atom in atransposition with respect to the carbonyl ligand; this was also confirmed by the IR and NMR data. The carbonyl stretching frequency ν(CO) and the carbonyl carbon1JC–Rhand1JC–Pcoupling constants of the Cipsoatoms of the triphenylphosphine groups reflect the diminished electron density on the central RhIatom compared to the parenttrans-[RhCl(CO)(PPh3)2] complex.

scholarly journals Darstellung und Charakterisierung einfacher α-Sila- und α,ω-Disilaalkane als Vorstufen für die CVD-Erzeugung von amorphem Silicium a-SiC:H / Synthesis and Characterization of Simple α-Sila- and α,ω-Disilaalkanes: Precursors for the CVD Production of Amorphous Silicon a-SiC:H

1987 ◽  
Vol 42 (9) ◽  
pp. 1088-1096 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Cornelia Dörzbach
Keyword(s):  
Amorphous Silicon ◽  
Spectroscopic Properties ◽  
High Yield ◽  
Synthesis And Characterization ◽  
Nmr Data ◽  
Functional Derivatives ◽  
New Compounds

Preparative methods have been explored for the synthesis of small, volatile polysilaalkanes, which could serve as starting materials for the production of amorphous silicon a-SiC:H. High yield pathways have been developed for H3SiCH2CH2SiH3 and H3SiCH2CH2CH2SiH3. These compounds can be converted into symmetrically halogen-functional derivatives through the reac­tions with SnCl4 or Br2. The homologous H3SiCH2CH2SiH2CH3 has also been prepared and halogenated, starting from the corresponding vinylsilane via the hydrosilylation route. Allylsilanes were the source of the synthesis of H3SiCH2CH=CH2, CH3SiH2CH2CH=CH, SiH2(CH2CH = CH2)2, SiH2(CH2CH2CH2SiH3)2, or HSi(CH2CH2CH2SiH3)3. Methylated deriva­tives are also available. - Some physical and spectroscopic properties of the new compounds have been investigated. In particular. NMR data were collected and used for an assessment of structure and isomerism.

Synthesis and Characterization of Indolylfulgide Photochromic Colorants

2013 ◽  
Vol 821-822 ◽  
pp. 522-526
Author(s):  
Ning Ning Lv ◽  
An Guo Sang ◽  
Yan Zhang
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
Synthesis And Characterization ◽  
Indole Derivatives ◽  
Thermal Stabilities ◽  
Nmr Data ◽  
New Compounds

This paper describes the synthesis of two photochromic 2-indolyl-fulgides by stobbe condensation of the corresponding 2-acyl-1,3-dimethyl-indole derivatives with diethyl isopropylidene succinate in the presence of hexamethyldisilazane potassium. The overall yields was up to 41% for 3 steps. Both prepared compounds are sensitive to UV light and change colors upon irradiation. And the two fulgides can be switched back and forth 100 times without obvious degradation. Thermal stabilities of the fulgides in acetonitrile at room temperature for 30 days and at 80 °C for 12 h were measured using UV-vis and 1H NMR spectroscopy. The absorption spectra of both forms did not exhibit any sign of degradation. The NMR data indicated that no new compounds were detected. The utilization of these materials for use in photochromic textiles were discussed.

scholarly journals Roussoelins A and B: two phenols with antioxidant capacity from ascidian-derived fungus Roussoella siamensis SYSU-MS4723

2020 ◽  
Author(s):  
Senhua Chen ◽  
Hongjie Shen ◽  
Yanlian Deng ◽  
Heng Guo ◽  
Minghua Jiang ◽  
...  
Keyword(s):  
Conformational Analysis ◽  
Antioxidant Capacity ◽  
Structural Properties ◽  
Coupling Constants ◽  
Bioactive Molecules ◽  
Active Metabolites ◽  
Nmr Data ◽  
Pharmacologically Active ◽  
New Compounds ◽  
Modified Mosher’S Method

Abstract Ascidian-derived microorganisms are a significant source of pharmacologically active metabolites with interesting structural properties. When discovering bioactive molecules from ascidian-derived fungi, two new phenols, roussoelins A (1) and B (2), and ten known polyketides (3–12) were isolated from the ascidian-derived fungus Roussoella siamensis SYSU-MS4723. The planar structure of compounds 1 and 2 was established by analysis of HR-ESIMS and NMR data. The conformational analysis of the new compounds was assigned according to coupling constants and selective gradient NOESY experiments, and absolute configurations were completed by the modified Mosher’s method. Among the isolated compounds, 1, 2, and 9 showed moderate antioxidant capacity. Graphical abstract

11B- und 13C-NMR-Spektroskopie von nido-Hexaalkyl-2.3.4.5-tetracarbahexaboranen(6) / 11B- und 13C-NMR Spectroscopy of nido-Hexaalkyl-2,3,4,5-tetracarbahexaboranes(6)

1982 ◽  
Vol 37 (4) ◽  
pp. 412-419 ◽  
Author(s):  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Coupling Constants ◽  
Triple Resonance ◽  
Triple Resonance Experiments ◽  
Nmr Data ◽  
Nuclear Shielding ◽  
C Nmr

11B and 13C NMR data of peralkylated nido-2,3,4,5-tetracarbahexaboranes(6) are reported. Application of selective heteronuclear triple resonance experiments 13C{1H,11B} enables to assign the structures of various isomers. The magnitude of the coupling constants 1J(11B11B), 1J(13C11B) and 1J(13C13C) is in accord with expectations based on the conception of bonding in carboranes. The comparison of δ11B and δ13C data of the nido- 2,3,4,5-tetracarboranes(6) with δ13C-data of corresponding non-classical carbocations shows the influence of charge upon the nuclear shielding of carbon in the latter.

Unsymmetrisch substituierte Phosphinoschwefeldiimide – NMR-Untersuchungen über die Konfiguration in Lösung/ Unsymmetrically Substituted Phosphino Sulfur Diimides – NMR Studies on the Configuration in Solution

1988 ◽  
Vol 43 (8) ◽  
pp. 985-992 ◽  
Author(s):  
Max Herberhold ◽  
Stefan M. Frank ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Low Temperatures ◽  
Room Temperature ◽  
Coupling Constants ◽  
Nmr Studies ◽  
Tert Butyl ◽  
Nmr Data

AbstractThe phosphino-substituted sulfur diimides S(N-PtBu2)2 (1), tBu;P(NSN)PRR′ (R = R′ - phenyl (2a), cyclohexyl (2b), isopropyl (2c), ethyl (2d); R = phenyl, R′ = tert-butyl (2e)) and tBu2P(NSN)tBu (3) were studied in solution by 1H, 13C and 31P NMR spectroscopy**. The coupling constants 4J(31P31P) of the compounds containing different phosphino groups, 2a-e, depend both on the nature of the solvent and the temperature. The NMR results are interpreted in accord with a rapid Z/E⇄ E/Z interconversion at room temperature and the predominance of a single configurational isomer at low temperatures. There is no indication for the presence of the “symmetrical” configurations, Z/Z or E/E respectively, in solution in appreciable amounts. 15N NMR data are also reported for a series of sulfur diimides.

Platinum(II) and Palladium(II) Dichalcogenolene Complexes Containing the Ligand Tri(1-cyclohepta-2,4,6-trienyl)phosphane. Molecular Structure, Intramolecular Dynamics in Solution, and the Absolute Signs of Coupling Constants 1J(195Pt, 77Se) and 2J(77Se, Pt, 31P)

2002 ◽  
Vol 57 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Max Herberhold ◽  
Thomas Schmalz ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Dynamic Process ◽  
Time Scale ◽  
Room Temperature ◽  
Coupling Constants ◽  
Intramolecular Dynamics ◽  
X Ray ◽  
The Absolute

Tri(1-cyclohepta-2,4,6-trienyl)phosphane, P(C7H7)3 (1), serves as a bidentate chelatinglig and [P] in platinum(II) and palladium(II) complexes. Here the synthesis of the four dichalcogenolene complexes [P]M[E2C2(CO2Me)2] (4) (M = Pt) and 5 (M = Pd) with E = S (a) and Se (b) from the reaction of the respective dicyclopentadienyltitanium dichalcogenolenes, Cp2Ti[E2C2(CO2Me)2], and [P]MCl2 with M = Pt (2) and Pd (3) is reported. At room temperature, the complexes 4 and 5 are fluxional with respect to the NMR time scale, and the nature of the dynamic process is discussed. The complexes have been characterised by 1H, 13C, 31P, 77Se and 195Pt NMR spectroscopy. The signs of the coupling constants 1J(195Pt, 77Se) (< 0) and 2J(77Se, 31P) (> 0) were obtained by selective 31P{195Pt} and 31P{77Se} spin tickling experiments. The crystal structure of 4b was determined by X-ray analysis.

Sign in / Sign up

Export Citation Format

Share Document