Determination of 31P,31P coupling constants in cyclotriphosphazenes and their influence on 1H and 13C NMR spectra of phosphorus substituents

¹H and ¹³C NMR spectra of symmetrically substituted cyclotriphosphazenes exhibit second‐order effects. The influence of the ³¹P,³¹P coupling constants between ring phosphorus atoms on these effects was studied. Some values of this coupling constant between phosphorus bearing identical substituents were measured using ¹³C satellites of the ³¹P signals or by introduction of a chiral substituent on the third phosphorus atom. Copyright © 2003 John Wiley & Sons, Ltd.     

Aminomethylphosphine Oxides: Synthesis,dissociation and stability constants, 31P{1H}-NMR-controlled titrations

The title compounds are prepared via Gabriel-synthesis following known or improved procedures. Novel methods using ³¹P{¹H}-NMR controlled titrations of aminomethylphosphine oxides lead to dissociation constants (given as basicity or acidity constants resp.) and to stability constants. Dynamically averaged and ion specific chemical shifts δ_P were derived.     

Complete 1H, 13C{1H}, and 31P NMR spectral parameters of some pyrophosphates

The ¹H, ¹³C{¹H}, and ³¹P NMR spectral parameters of some pyrophosphates were determined in CDCl₃. The most complicated ¹H spectrum can be solved fully only as (A₃MN)R₆XX′R₆′(MNA₃)′, where R₆ (= ―N(CH₃)₂) is coupled only to phosphorus (X). Second‐order coupling between phosphorus was found and solved with iterative analysis. A signal shape of one of the carbon resonance cannot be explained only with couplings. Explanation for exceptional shape was searched from molecular modeling results. Copyright © 2017 John Wiley & Sons, Ltd.     

Layered metal(IV) phosphonate materials: Solid‐state 1H, 13C, 31P NMR spectra and NMR relaxation

Multinuclear solid‐state NMR and powder X‐ray diffraction data collected for phosphonate materials Zr(O₃PC₆H₄PO₃) · 3.6H₂O and Sn(O₃PC₆H₄PO₃)_0.85(O₃POH)_0.30 · 3.09H₂O have resulted in the layered structure, where the phosphonic acids cross‐link the layers. The main structural motif (the 111 connectivity in the PO₃ group) has been established by determination of chemical shift anisotropy parameters for phosphorus nuclei in the phosphonate groups. An analysis of the variable‐temperature ³¹P T₁ measurements and the shapes of the phosphorus resonances in the ³¹P static NMR spectra have resulted in the dipolar mechanism of the phosphorus spin‐lattice relaxation, where the rotating phenylene rings reorient dipolar vectors P^…H as a driving force of the relaxation process. It has been found that water protons do not affect the ³¹P T₁ times. The activation energy of the phenylene rotation in both compounds has been determined as low as 12.5 kJ/mol. The interpretation of the phosphorus relaxation data has been independently confirmed by the measurements of ¹H T₁ times for protons of the phenylene rings.     

19F and 1H NMR spectra of halocarbons

19F NMR chemical shifts and coupling constants are reported for 215 compounds. For 77 of these compounds, 1H NMR spectral data are also given. Long-range couplings, including 8J(F,F) and 5J(F,H), are reported. The complexity of halocarbon spectra owing to the presence of rotational isomers, asymmetric centers, long-range couplings, and chlorine isotope effects are illustrated, and the methods used for analyzing such complex spectra are briefly discussed.     

Complete 1H, 13C, 19F and 31P NMR data assignment of CWC‐related chemicals N,N‐dialkyl‐P‐alkyl phosphonamidic fluorides

The complete multinuclear ¹H, ¹³C, ³¹P and ¹⁹F NMR data of symmetrically substituted amines containing N,N‐dialkyl‐P‐alkyl phosphonamidic fluorides are presented. Assignment was achieved, using various one‐and two‐dimensional NMR experiments. Copyright © 2010 John Wiley & Sons, Ltd.     

含硫有机膦多酸衍生物α–[RP(S)]2PW9O345-(R = –C6H5, –C6H11)的合成及结构表征

In the presence of Bu4NBr acting as phasetransfer reagent, organothiophosphoryl polyoxotungstate derivatives α-[RP(S)]2PW9O54^5- (R=C6Hs, C6H11) have been obtained by reaction of the trivacant β-[PW9O34]^9- anions with electrophilic C6H5P(S)Cl2 or C6H11P(S)Cl2 in acetonitrile. These new organic-inorganic hybrid anions have been characterized by elemental analysis, IR, ^31P and ^183W NMR spectroscopy. The collective application of the spectroscopy data of these new species indicates that the hybrid anion consists of an α-[PW9O34] framework on which are grafted two RP(S) groups through P-O-W bridges. The five-line ^183W spectra indicate that the hybrid anions possess Cs symmetry in acetonitrile.     

1H and 13C NMR spectra of N-substituted morpholines

(1)H and (13)C NMR data for N-substituted morpholines 1-20 were measured using 1D (DEPT, 1D NOE difference) and 2D NMR spectroscopic methods including (1)H-(1)H COSY, long-range (1)H-(1)H COSY, NOESY, gHMBC and gHMQC experiments. At room temperature the (1)H NMR spectra of protonated compounds 2 and 9 show the chair conformation for the morpholine ring. Spin-spin coupling constants were deduced from the resolution-enhanced proton spectra.     

A 1H, 13C, 31P and 15N NMR study of (pyrrolidine-2,2-diyl)bisphosphonic acid,tetraalkyl(pyrrolidine-2,2-diyl)bisphosphonates and acyclic tetraethyl bisphosphonates

A multinuclear magnetic resonance study (¹H, ¹³C, ³¹P, ¹⁵N) was performed on a series of new cyclic pyrrolidine bisphosphonates and acyclic bisphosphonates. Values are reported and discussed for the chemical shifts and coupling constants of the various nuclei. Copyright © 2000 John Wiley & Sons, Ltd.     

Indirect detection of 31P,X connectivities with proton sensitivity: application of two‐dimensional 31P‐relayed 1H,X correlation spectroscopy

Experiments for ¹H‐detected heteronuclear ¹H,X correlation spectroscopy with ³¹P‐relayed coherence transfer are described which allow the indirect detection of δX and ⁿJ(X,P) even in the absence of a direct J(X,H) coupling. The use of these techniques for the assignments of ¹³C, ¹⁵N, and ¹⁸³W NMR data of organophosphorus compounds is demonstrated. Copyright © 2003 John Wiley & Sons, Ltd.     

1H, 13C and 31P NMR spectral analysis of monoalkyl (α‐anilinobenzyl)phosphonates and their dipalladium(II) metallocyclic complexes

A ¹H, ¹³C and ³¹P NMR study of monoethyl (HL1) and monobutyl (HL2) esters of (α‐anilinobenzyl)phosphonic acid and their metallocyclic dipalladium complexes (Pd₂L₄,L = L1, L2) in DMSO‐d₆ was performed, based on 1D and 2D homo‐ and heteronuclear experiments including ¹H,¹³C,³¹P,APT,¹H–¹H COSY, ¹H–¹³C COSY, gs‐HMQC and gs‐HMBC NMR techniques. The results obtained are discussed with respect to those for some palladium(II) complexes reported for various anilinobenzylphosphonate derivatives. Copyright © 2002 John Wiley & Sons, Ltd.     

Complete assignment of the 1H and 13C NMR spectra of some N‐benzyl‐(piperidin or pyrrolidin)‐purines

The ¹H and ¹³C shifts of six N‐benzyl‐(piperidin or pyrrolidin)‐purines were fully assigned by a combination of HSQC and HMBC experiments. The ¹H,¹H coupling constants were also determined. Copyright © 2002 John Wiley & Sons, Ltd.     

Reaction of Os3(μ-Cl)2(CO)10 with Ph2PCH2PPh2. The formation of a novel 12-membered macrocycle containing C, P, Cl, and Os atoms in the ring

The reaction of Os₃(μ-Cl)₂(CO)₁₀ (1) with Ph₂PCH₂PPh₂ (dppm) in a toluene solution at 65°C results in novel osmium complexes [Os₃(μ-Cl)₂(CO)₉]₂(dppm) (2) and [Os₃(μ-Cl)₂(CO)₈]₂(dppm)₂ (3). Compounds 2 and 3 were characterized by¹H and³¹P NMR, and IR spectroscopy and their structures were established by X-ray analysis. In both compounds, dppm is a bridging ligand between the two cluster units. Molecule3 can be considered as an unusual 12-membered macrocycle containing C, P, Cl, and Os atoms in the ring. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1844–1851, September, 1998.     

Phosphorylated amino acids: model compounds for solid-state 31P NMR spectroscopic studies of proteins

Solid-state 31P NMR spectroscopy was applied to measure the isotropic chemical shifts, chemical shift anisotropies and asymmetry parameters of three phosphorylated amino acids, O-phospho-L-serine, O-phospho-L-threonine and O-phospho-L-tyrosine. The cross-polarization buildup rates and longitudinal relaxation times of 31P and 1H were-determined and compared with the values measured for a triphosphate (GppCH2p) bound to a crystalline protein (Ras). It is shown that the phosphorylated amino acids are well-suited model compounds, e.g. for the optimization of experiments on crystalline proteins. Two-dimensional exchange experiments on O-phospho-L-tyrosine indicate the existence of an exchange between the two different conformations of the molecule.     

1H NMR spectra part 31: 1H chemical shifts of amides in DMSO solvent

The ¹H chemical shifts of 48 amides in DMSO solvent are assigned and presented. The solvent shifts Δδ (DMSO‐CDCl₃) are large (1–2 ppm) for the NH protons but smaller and negative (?0.1 to ?0.2 ppm) for close range protons. A selection of the observed solvent shifts is compared with calculated shifts from the present model and from GIAO calculations. Those for the NH protons agree with both calculations, but other solvent shifts such as Δδ(CHO) are not well reproduced by the GIAO calculations. The ¹H chemical shifts of the amides in DMSO were analysed using a functional approach for near ( ≤ 3 bonds removed) protons and the electric field, magnetic anisotropy and steric effect of the amide group for more distant protons. The chemical shifts of the NH protons of acetanilide and benzamide vary linearly with the π density on the αN and βC atoms, respectively. The C=O anisotropy and steric effect are in general little changed from the values in CDCl₃. The effects of substituents F, Cl, Me on the NH proton shifts are reproduced. The electric field coefficient for the protons in DMSO is 90% of that in CDCl₃. There is no steric effect of the C=O oxygen on the NH proton in an NH…O=C hydrogen bond. The observed deshielding is due to the electric field effect. The calculated chemical shifts agree well with the observed shifts (RMS error of 0.106 ppm for the data set of 257 entries). Copyright © 2014 John Wiley & Sons, Ltd.     

Die Reaktion von tBu2P‐P=P(Me)tBu2 mit [Fe2(CO)9] und [(η2‐C8H14)2Fe(CO)3]

^tBu₂P‐P=P(Me)^tBu₂ reacts with [Fe₂(CO)₉] to give [μ‐(1, 2, 3:4‐η‐^tBu₂P¹‐P²‐P³‐P^4tBu₂){Fe(CO)₃}{Fe(CO)₄}] ( 1 ) and [trans‐(^tBu₂MeP)₂Fe(CO)₃]( 2 ). With [(η²‐C₈H₁₄)₂Fe(CO)₃] in addition to [μ‐(1, 2, 3:4‐η‐^tBu₂P¹‐P²‐P³‐P^4tBu₂){Fe(CO)₂PMe^tBu₂}‐{Fe(CO)₄}] ( 10 ) and 2 also [(μ‐P^tBu₂){μ‐P‐Fe(CO)₃‐PMe^tBu₂}‐{Fe(CO)₃}₂(Fe‐Fe)]( 9 ) is formed. 1 crystallizes in the monoclinic space group P2₁/c with a = 875.0(2), b = 1073.2(2), c = 3162.6(6) pm and β = 94.64(3)?. 2 crystallizes in the monoclinic space group P2₁/c with a = 1643.4(7), b = 1240.29(6), c = 2667.0(5) pm and β = 97.42(2)?. 9 crystallizes in the monoclinic space group P2₁/n with a = 1407.5(5), b = 1649.7(5), c = 1557.9(16) pm and β = 112.87(2)?.     

Dependence of geminal1H−1H and31P−1H spin-spin coupling constants on the specific intramolecular C−H...X interaction

Participation of the proton in a specific intramolecular C−H...X (X=N, 0) interaction leads to an increase in its geminal¹H−¹H and¹H−³¹P spin-spin coupling constants (SSCC). According toab initio calculations carried out in the 6–31G^** basis set, the observed effect is mainly due to the change in the diamagnetic spin-orbital contribution to SSCC. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 306–309, February, 1997.     

Towards the automatic analysis of 1H NMR spectra: Part 4--additional requirements of flow-NMR

Flow-NMR allows more rapid and convenient acquisition of NMR spectra. Its main application area has therefore been in multiple parallel synthesis or combinatorial chemistry. At the same time, there is a significant need to automate the analysis of the resultant spectra. However, flow-NMR brings spectral imperfections, which compromise attempts to automate this analysis. This study proposes experimental and computational expedients to accommodate the effects of residual solvent peaks, 13C satellites, finite signal-to-noise ratio, impurities, presaturation on integral calculations, the 'silent' region and how multiplet areas can be scaled to numbers of protons in this environment.     

Determination of (3)J((1)H3'-(31)P) couplings in a DNA oligomer with enhanced sensitivity employing a constant-time TOCSY difference experiment

A constant-time TOCSY difference experiment for the determination of (3)J((1)H3'-(31)P) coupling constants in non-isotope-labelled DNA oligonucleotides is presented. The method is tested on a DNA octamer and compared with the established constant-time NOESY difference method. Each (3)J((1)H3'-(31)P) coupling constant is determined from amplitude changes caused by phosphorous decoupling, which are observable on multiple cross-peaks, thus leading to a high accuracy of the value of the (3)J((1)H3'-(31)P) coupling constant. The new experiment delivers up to three times the sensitivity compared with previously reported methods.