31P CP/MAS NMR spectra

Figure 20 (Left) 31P CP/MAS NMR spectra of Na2ATP crystals in variety of relative humidities (given in percents) (taken from Ref. [78]). (Right) 31P-31P POST-C7 correlation spectra for disodium ATP hydrates recorded at 287 K (spinning rate 10 kHz, RF 70 kHz and excitation time (fex) 1.4 ms) (A) trihydrate, (B) dihydrate and (C) monohydrate. Taken from Ref. [52].

Indium. Homo- and heteronuclear indirect spin-spin interactions in InP semiconductors were studied by 31P CP/MAS-NMR.423 31P CP/MAS-NMR spectra were obtained for undoped and Fe-doped InP semiconductors.424... 

P CP-MAS-NMR spectra of the solid complexes of various Ag(I)X salts with l,3-bis(diphenylphosphino)propane (dppp) pointed to two different types of complex, [Ag(dppp)2]+ and [Ag(dppp)X] (item P-2 in Table 3). 31P NMR of the dissolved complexes showed that equilibration takes place between both complex types208. 13C CP-MAS-NMR spectra of the polymeric complex 142 (item N-9 in Table 3) pointed to two different types of carboxylate groups in the phthalate anion221. 

Fig. 9 Examples of simplifying solid state NMR spectra by the TOSS and delayed decoupling pulse sequences. Shown is a comparison of the 31P CP/MAS NMR spectrum of fosinopril sodium utilizing the standard pulse sequence (A) and the TOSS routine (B). Also shown is the full 13C CP/MAS NMR spectrum of fosinopril sodium (C) and the nonprotonated carbon spectrum (D) obtained from the delayed decoupling pulse sequence utilizing a 80 /us delay time. Signals due to the methyl carbon resonances (0-30 ppm) are not completely eliminated due to the rapid methyl group rotation, which reduces the carbon-proton dipolar couplings.

MAS NMR spectra were obtained with a Bruker 400 MSL spectrometer. The experimental conditions used in the 29Si DEC, 29Si CP, 27Al, 27A1 CP and 31P DEC were as follows ... 

Figure 9. 27A1, 29si, 29Si CP and 31P MAS NMR spectra of MCM-1 sample No.27.

Another class of inclusion complexes containing phosphorus in the host structure are cyclophosphazenes. Sozzani and co-workers have reported 31P CP/MAS studies of two organic derivatives tris(o-phenylene-dioxy)cyclotriphosphazene (TPP) and tris(2,3-naphtalene-dioxy)cyclotri-phosphazene (TNP). In the cited works, SS NMR technique was employed to recognise guest-free TNP matrix and of ICs with guests, for example benzene, tetrahydrofuran and p-xylene. The 31P NMR spectra were particularly informative regarding the symmetry of the phos-phazene ring. 

Despite that 31P NMR spectra can be recorded in a simple one-pulse (Bloch decay) experiment, very often MAS technique is combined with CP. CP under MAS has been extensively studied in the past.17 18... 

Figure 46 (Top) Experimental 31P NMR spectra of three component sample crystallised from toluene (A) powdered sample (PS) recorded with CP/MAS sequence and spinning rate 8 kHz (B) three-component single crystal (TCSC) A held in rotor filled with silica gel recorded with CP/MAS sequence and spinning rate of 8 kHz. Note the much better NMR resolution of resonance lines and small distinction of 31P chemical shifts for the monocrystal compared to powdered sample. (Bottom) 31P-31P proton-driven spin diffusion 2D correlation recorded with mixing times of (A) 0.2 and (B) 10 s. Taken from Ref. [229].

Figure 15.21. CP/MAS spectra l3C inp-dimethoxybenzene (note splitting induced in ortho carbons due to the asymmetry of the methoxy group), 29Si in poly-[dimethy lsiloxane) (PDMS), and 31P in bone mineral [roughly equivalent to Ca50H(P04)3]. (29Si spectrum reprinted with permission from Beshah K, Mark JE, Himstedt A, Ackerman JL. Characterization of PDMS model junctions and networks by solution and solid state silicon-29 NMR spectroscopy. J Polymer Sci B Polymer Phys. 1986 24 1207-1225. Copyright 1986 John Wiley Sons.)...

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