scholarly journals Synthesis and Characterization of Aza-Trimetalla Tetrahedranes

1996 ◽  
Vol 51 (11) ◽  
pp. 1621-1626 ◽  
Author(s):  
Max Herberhold ◽  
Uwe Bertholdt ◽  
Bernd Wrackmeyer
Keyword(s):  
Nitrogen Atom ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Synthesis And Characterization ◽  
Exchange Reactions ◽  
H Nmr ◽  
A Minor

The sulfimide complex Fe2(CO)6(μ-SNH) (1) reacts with Co2(CO)8 to form a 1:1 mixture of the known clusters FeCo2(CO)9(μ3-S) (2) and FeCo2(CO)9(μ3-NH) (3). The azatetrahedrane 3 may be used as a precursor for the synthesis of the new aza-trimetalla tetrahedranes Fe2Co(CO)9(μ-H)(μ3-NH) (5), CpMoFeCo(CO)8(μ3-NH) (6), CpNiFeCo(CO)6(μ3-NH) (7) and (CpNi)2Fe(CO)3(μ3-NH) (8) which were obtained from exchange reactions of 3 with Na2[Fe(CO)4], Na[CpMo(CO)3] and [CpNi(CO)]2. However, the reactions of 3 with Na2[Fe(CO)4] and Fe3(CO)12 gave Fe3(CO)9(μ-H)2(μ3-NH) (9) only as a minor product in addition to large amounts of Fe3(CO)9(μ-H)2(μ3-S) (10). The 1H NMR spectra of 3 and 5 - 9 show a broadened triplet for the NH proton between δ(1H) 8.21 and 9.53. Chemical shifts δ(14N) were determined most efficiently by heteronuclear 1H {14N} double resonance experiments. The δ(14N) values for aza-trimetalla tetrahedranes (-180 to -202) indicate delocalized bonding between the μ3-bridging nitrogen atom and the metal triangle.

13C-NMR-Spektroskopie an polycyclischen Aromaten, II. Die 13C-NMR-Spektren von 1- und 2-Fluornaphthalin. Überprüfung der Signalzuordnung und Untersuchung der Substituenteneffekte auf die chemischen Verschiebungen / 13C NMR Spectroscopy of Polycyclic Aromatics, II. The 13C NMR Spectra of 1- and 2-Fluoronaphthalene. Reexamination of Signal Assignments and Investigation of Substituent Effects on Chemical Shifts

1975 ◽  
Vol 30 (9-10) ◽  
pp. 788-793 ◽  
Author(s):  
Ludger Ernst
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Substituent Effects ◽  
13C Nmr Spectroscopy ◽  
Polycyclic Aromatics ◽  
H Nmr ◽  
Iterative Analysis ◽  
C Nmr

During a reinvestigation of the 13C NMR spectra of 1-fluoronaphthalene (1) and of 2-fluoronaphthalene (2) at 20 and 25.16 MHz, uncertainties that existed in the literature about signal assignments for 1 could be cleared. In the spectral analyses for 2 given so far, five out of ten signals were incorrectly assigned. The corrected assignment is supported by extensive 13C{1H} double resonance experiments, by recording of proton-coupled 13C and 13C{19F} spectra and by off-resonance 13C{1H} noise-decoupling. The results show a strong + M-effect of the fluorine substituents on 13C chemical shifts similar to the effects of OH and OCH3 groups. 1H NMR spectra of 1 and 2 could be partially assigned by decoupling of the 19F resonances and by iterative analysis.

Synthesis and characterization of several series of 4-acyl-1-[2-aryl-1-diazenyl]piperazines

2014 ◽  
Vol 92 (9) ◽  
pp. 838-848 ◽  
Author(s):  
Vanessa Renee Little ◽  
Keith Vaughan
Keyword(s):  
High Resolution ◽  
Ir Spectroscopy ◽  
Chemical Shifts ◽  
Synthesis And Characterization ◽  
Model Compounds ◽  
Primary Aromatic Amine ◽  
Piperazine Ring ◽  
H Nmr ◽  
C Nmr

Five series of a novel class of 4-acyl-1-[2-aryl-1-diazenyl]piperazines have been synthesized and characterized: the 4-acetyl-1-[2-aryl-1-diazenyl]piperazines [series 1]; the 4-cyclohexylcarbonyl-1-[2-aryl-1-diazenyl]piperazines [series 2]; the 4-benzoyl-1-[2-aryl-1-diazenyl]piperazines [series 3]; the benzyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates [series 4]; and the t-butyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates [series 5]. The compounds were synthesized by diazotization of a primary aromatic amine and subsequent coupling to an appropriate secondary amine: 1-acetylpiperazine [series 1]; 1-(cyclohexylcarbonyl)-piperaizine [series 2]; 1-benzoylpiperazine [series 3]; benzyl 1-piperazinecarboxylate [series 4]; and t-butyl piperazine-1-carboxylate (1-BOC-piperazine) [series 5]. The compounds of series 1–5 were characterized by 1H NMR, 13C NMR, high-resolution MS and IR spectroscopy. The model compounds 1,4-di[2-aryl-1-diazenyl]piperazines, and ethyl 4-[2-aryl-1-diazenyl]-1-piperazinecarboxylates were used to facilitate the assignment of the chemical shifts specific to the piperazine ring carbons. HSQC spectra of select compounds established the correlation between proton and carbon resonance signals.

Phenylsilane dehydrocoupling and addition to styrene catalyzed by (R-indenyl)Ni(phosphine)(methyl) complexes

2009 ◽  
Vol 87 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Yaofeng Chen ◽  
Davit Zargarian
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Variable Temperature ◽  
Structural Parameters ◽  
Catalytic Cycle ◽  
Synthesis And Characterization ◽  
H Nmr ◽  
Solid State Structures ◽  
Indenyl Complexes

This report describes the synthesis and characterization of the Ni–Me complexes (R-indenyl)Ni(PR′3)Me (R = 1-i-Pr, 1-SiMe3, and 1,3-(SiMe3)2; R′= Me, Ph) and outlines their catalytic reactivities in the dehydrogenative oligomerization of PhSiH3 and its addition to styrene in the absence of initiators/activators. Observation of higher hydrosilylation activities for PPh3-based compounds featuring bulky substituents on the indenyl ligand confirms earlier suggestions that phosphine dissociation is an important component of the catalytic cycle for this reaction. In contrast, oligomerization of PhSiH3 is more facile with PMe3-based precursors and independent of the steric bulk of the indenyl ligand, implying that this reaction does not involve phosphine dissociation. These conclusions are consistent with the variable-temperature 1H NMR spectra of {1,3,-(SiMe3)2-indenyl}Ni(PR′3)Me and various structural parameters observed in the solid-state structures of {1,3,-(SiMe3)2-indenyl}Ni(PPh3)Me, {1,3,-(SiMe3)2-indenyl}Ni(PMe3)Cl, and {1-SiMe3-indenyl}Ni(PMe3)Me.Key words: nickel-indenyl complexes, hydrosilylation, hydrosilane oligomerization.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF C-HEXYL CALIX[4]RESORCINARENA FROM RESORCINOL-HEPTANAL CONDENSATION

2016 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Desi Suci Handayani ◽  
Zainal Arifin Almaqqomul Amin ◽  
Triana Kusumaningsih ◽  
Abu Masykur
Keyword(s):  
Melting Point ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Chemical Shifts ◽  
Condensation Reaction ◽  
Wave Number ◽  
Synthesis And Characterization ◽  
H Nmr ◽  
Brown Powder

<p>Synthesis of  C-hexyl  calix[4]resorcinarene  through condensation reaction between resorcinol  and  heptanal  with  HCl  catalyst  has  been  investigated.  Synthesis  conducted  by the ratio of resorcinol: heptanal (1:1) using reflux for 6 hours in ethanol. Structural  analysis of  the  product  was  done  by  FTIR  and 1 H-NMR  spectroscopy,  while  the  characterization was  done  by  determining  melting  point.  The  product  was  golden  brown  powder  with  a yield 99.43%  and  melting point more than 300 °C.  Structural analysis with FTIR and 1 HNMR  known  vibration  and  signals  characteristic  of  calix[4]resorcinarena  group, the vibrations of the CH  bridge. Vibration of CH bridge appearance at wave number 1445 cm<sup>-1</sup> and 1456  cm<sup>-1</sup>, while signal of CH bridge appearance at chemical shifts from  4.17 to 4.21 ppm.</p>

SYNTHESIS AND CHARACTERIZATION OF C-HEXYL CALIX[4]RESORCINARENA FROM RESORCINOL-HEPTANAL CONDENSATION

2014 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Desi Suci Handayani
Keyword(s):  
Melting Point ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Chemical Shifts ◽  
Condensation Reaction ◽  
Wave Number ◽  
Synthesis And Characterization ◽  
H Nmr ◽  
Brown Powder

<p>Synthesis of C-hexyl calix[4]resorcinarene through condensation reaction between resorcinol and heptanal with HCl catalyst has been investigated. Synthesis conducted by the ratio of resorcinol: heptanal (1:1) using reflux for 6 hours in ethanol. Structural analysis of the product was done by FTIR and <sup>1</sup>H-NMR spectroscopy, while the characterization was done by determining melting point. The product was golden brown powder with a yield 99.43% and melting point more than 300 °C. Structural analysis with FTIR and <sup>1</sup>H-NMR known vibration and signals characteristic of calix[4]resorcinarena group,the vibrations of the CH bridge. Vibration of CH bridge appearance at wave number 1445 cm<sup>-1</sup> and 1456 cm<sup>-1</sup>, while signal of CH bridge appearance at chemical shifts from 4.17 to 4.21 ppm.</p>

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.

Beiträge zur Chemie des Phosphors, 49.

1972 ◽  
Vol 27 (12) ◽  
pp. 1451-1456 ◽  
Author(s):  
Peter Junkes ◽  
Marianne Baudler ◽  
Jürgen Dobbers ◽  
Dieter Rackwitz
Keyword(s):  
Low Temperature ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
H Nmr ◽  
Auxiliary Substance ◽  
Temperature Standard

The 31P- and 1H-NMR spectra of PH3, PD3, P2H4, P2D4, P3H5, and of a mixture of higher phosphanes were investigated at -60° to -93°C. The chemical shifts of the 31P-spectra were determined against TMS by means of INDOR measurements and converted to the shifts against 85% H3PO4 at 30°C using (CH3O)3P as an auxiliary substance. By the same method a P4O6/CS2 solution was calibrated as a 31P-low temperature standard.While liquid P2H4 exhibits no remarkable association, it shows an obvious influence on PH3 dissolved in it. By means of double resonance experiments the equivalency of protons in P2H4 could be demonstrated as well as the AB2 system expected for P3H5

scholarly journals Synthesis and characterization of azetidin-2-one and 1,3-oxazepine derivatives using Schiff bases derived from 1,1’-biphenyl-4,4’-diamine

2021 ◽  
Vol 2063 (1) ◽  
pp. 012010
Author(s):  
H D Hanoon ◽  
H A Abd Al Hussain ◽  
S K Abass
Keyword(s):  
Schiff Bases ◽  
Heterocyclic Compounds ◽  
Nmr Spectra ◽  
Condensation Reaction ◽  
Synthesis And Characterization ◽  
Chloroacetyl Chloride ◽  
H Nmr ◽  
Ft Ir ◽  
Benzaldehyde Derivatives

Abstract The present study included the synthesis of two series of heterocyclic compounds, azetidin-2-one and 1,3-oxazepine derivatives. All synthesized compounds were characterized using FT-IR and 1H NMR spectra. The study was divided into two parts. The first synthesis Schiff bases derivatives (1-4) via the condensation reaction of 1,1′-biphenyl-4,4′-diamine (A) with benzaldehyde derivatives (2,5-dimethoxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, furan-2-carbaldehyde and 3-hydroxybenzaldehyde). The second synthesis azetidine-2-one derivatives (5-8) from the reaction of Schiff bases with chloroacetyl chloride. Schiff bases also reacted with maleic anhydride to yield 1,3-oxazepine derivatives (9-12).

Synthese und Charakterisierung der Spezies R–C7H7Cr(CO)3 mit R = CH3COCH2-, CH3CO(CH3)CH-, CH3COCHCH(CH3)2– / Synthesis and Characterization of the Species R-C7H7Cr(CO)3 with R = CH3COCH2-, CH3CO(CH3)CH - , CH3COCHCH(CH3)2–

1979 ◽  
Vol 34 (7) ◽  
pp. 918-920 ◽  
Author(s):  
Farhad Zahedi ◽  
Manfred L. Ziegler
Keyword(s):  
Carbon Atom ◽  
Nucleophilic Addition ◽  
Nmr Spectra ◽  
Synthesis And Characterization ◽  
Ethyl Group ◽  
H Nmr

Abstract The species R-C7H7Cr(CO)3 (R = -CH2COCH3 , -CH(CH3)COCH3 , -CH(CH)CH3)2COCH3) have been synthesized by reaction of [η7-C7H7Cr(CO)3][BF4] with suitable ketones in the presence of bases like OH- and F- , suggesting a nucleophilic addition of the enolate ion to the cycloheptatrienyl ligand. 1H NMR spectra revealed the CH3-CO-CH(CH3) group being bonded to the cycloheptatriene ligand via the a-carbon atom of the ethyl group

Synthesis and Characterization of Palladium Complexes Containing 3,3'-Annelated 2,2'-Bipyridines and 3,3'-Annelated 2,2'-Biquinolines

1997 ◽  
Vol 62 (2) ◽  
pp. 238-256 ◽  
Author(s):  
René A. Klein ◽  
Ruud van Belzen ◽  
Kees Vrieze ◽  
Cornelis J. Elsevier ◽  
Randolph P. Thummel ◽  
...  
Keyword(s):  
Time Scale ◽  
Nmr Spectra ◽  
Palladium Complexes ◽  
Synthesis And Characterization ◽  
Saturation Transfer ◽  
Transfer Experiment ◽  
Space Group ◽  
H Nmr ◽  
Entropy Of Activation

The synthesis and characterization of a number of PdCl2(N⁀N) and Pd(N⁀N)(fn) complexes (N⁀N = 3,3'-annelated 2,2'-bipyridines and 3,3'-annelated 2,2'-biquinolines, fn = fumaronitrile) have been described. Despite the variation in dihedral angle and distance between the nitrogen lone pairs in these series of ligands, they are all capable of forming stable chelates. An investigation was made as to whether the 3,3'-trimethylene-2,2'-biquinoline (3-bq) and 3,3'-tetramethylene-2,2'-biquinoline (4-bq) ligands could serve as C2-chiral auxiliaries. The ligand 3-bq in Pd(3-bq)(fn) turned out to be conformationally rigid on the NMR time scale, but the diastereomers appeared to be indistinguishable, as could be concluded from the 1H NMR spectra. However, Pd(4-bq)(fn) exists in two diastereomeric forms and their ratio (57 : 43) could be determined from 1H NMR spectra. Assignment of the major and minor isomers was done with a 2D NOESY experiment. Epimerization of the diastereomers occurred on the laboratory time scale which was deduced from a spin saturation transfer experiment and also from the observation that diastereomerically enriched crystalline material of Pd(4-bq)(fn) at low temperature showed a ratio of 80 : 20 which deteriorated to a ratio of 57 : 43. From the spin saturation transfer experiment, the thermodynamic parameters for the inversion could be determined (∆H≠ = 29.1 kJ mol-1 and ∆S≠ = -136.3 J K-1 mol-1). This large negative entropy of activation favours an epimerization process via inversion of the coordinated 4-bq ligand over a mechanism via alkene dissociation/recoordination. The structures of the complexes have been studied in solution and in the solid state and the following X-ray crystal structures have been determined: (i) [dichloropalladium(II)](3,3'-trimethylene-2,2'-bipyridine-κ2N), monoclinic crystals, space group P21/n, with a = 8.4230(7) Å, b = 16.425(2) Å, c = 9.5836(7) Å, β = 106.316(7)°, Z = 4, final R = 0.033 for 2 309 reflections, (ii) [3,3'-bis(methoxycarbonyl)-2,2'-bipyridine-κ2N][dichloropalladium(II)], triclinic crystals, space group P1, with a = 7.340(4) Å, b= 10.012(3) Å, c= 11.954(3) Å, α = 98.10(2)°, β = 104.03(3)°, γ = 107.33(5)°, Z = 2, final R = 0.039 for 4 273 reflections, (iii) [chloromethylpalladium(II)](4,5-diazafluorene-κ2N), orthorhombic crystals, space group Pmcn, with a = 6.713(1) Å, b = 10.120(1) Å, c = 17.187(3) Å, Z = 4, final R = 0.048 for 949 reflections.

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