NMR spectroscopy elemental analysis

Here we report on the synthesis of some new cage compounds from various chlorool osilanes and (Na/K)3P or (Na/K)3As under carefiilly chosen reaction conditions. They were characterized by and NMR spectroscopy, elemental analysis, and IR and Raman spectroscopy. The crystal structures were elucidated by X-ray crystallography. 

The microstructure and particle morphology (size, shape, and surface roughness) of the colloids were studied with 13C and 29Si NMR spectroscopy, elemental analysis, transmission electron microscopy, and static and dynamic light scattering. 

Powder X-ray diffraction solid-state NMR spectroscopy Raman/IR spectroscopy thermal analysis Solution NMR spectroscopy elemental analysis Karl-Fisher titration evolved gas analysis... 

NMR spectroscopy Elemental composition by specific analysis Protein pattern by Electrophoresis... 

With Na3As/K3As the tetrachlorodecamethylhexasilane (Me2ClSi)2SiMeSiMe(SiMe2Cl)2 [7] forms dodecamethyl-l,3-diarsa-2,4,5,6,7,8,9-heptasilatricyclo[3.2.1.1 tion3iic- Its structure was confirmed by mass spectroscopy, elemental analysis, and Si NMR spectroscopy (Fig. 6). 

The reaction of the terminal borylene [(OC)sM=B=N(SiMe3)2] (M = Cr, W) compounds with [ RhCl(CO)2 2] in deuterated benzene for a few minutes led to formation of a tetranuclear rhodium bis-borylene compound as black crystals 18a. The bis-borylene derivative possesses two fused B-Rh-Rh, dirhodium-borirane rings <2006AGE2132>. Compound 18a was characterized by multinuclear NMR and infrared spectroscopy, elemental analysis and single crystal X-ray diffraction. The B NMR (C6D6) spectrum presents a single signal at 74 ppm, a low frequency shift when compared with similar systems, which normally appear between 98 and 120 ppm. 

Reaction monitoring is highly facilitated as routine experiments such as II NMR, 13C NMR, mass spectrometry, IR spectroscopy, elemental analysis can be performed. This is mainly due to the simplicity of the structure. Unlike polymeric supports where signals from the support often prevent accurate measurement of conversion or side product concentration, trimethylammonium salts have only a limited effect on NMR spectra with a singlet and a multiplet in the 3.0-3.2 ppm region. Additionally onium salt supported products can eventually be analyzed using HPLC and mass spectrometry. 

These materials are characterized by common techniques such as H NMR, IR, elemental analysis, DSC, and TGA.54 58 59 60 64 68 Other techniques such as electron spin resonance (ESR),54 magnetic susceptibilities54 and Mossbauer spectroscopy (when they apply),56,58 60 64 71 uV-visible spectroscopy,58,59 60 61 64-67 and solid-state electric conductivity measurements5456 59-63 66 67 71 were also employed. These materials were carefully compared to model bis(mono-isocyanide) adducts for better understanding of the physical properties. Important solubility problems are often observed when no alkyl side chain is used. So, these more soluble substituents are incorporated either on the macrocycles or the bridging ligands for better characterization. 

Linear 1-D polymers of the type M(diphos)(CN-t-Bu)2 n (M = Cu, Ag diphos = dppb, dpppen, dpph) and Ag(dpppen)(CN-r-Bu)+ (86-92) were recently prepared and fully characterized by H, 13C, 31P NMR, IR, elemental analysis, X-ray structures (for 90 and 92), DSC, TGA, XRD, and electronic spectroscopy.96 The polymers are weakly soluble in CH3CN, CH2C12, methanol, and CHC13, allowing for better characterization. The materials are stable to at least 150°C (TGA) and photochemically stable to sunlight, at least for several months. The TGA traces are characterized by two thermal events between 150 and 350°C. The first weight loss is due to CN-r-Bu, and the second, to the diphosphine ligands. 

The reaction of equimolar quantities of the ligand 4,6-bis(6-(2,2 -bipyrid-yl))-pyrimidine 1 (or the methyl substituted analogs 2, 2) and Co(II)acetate in refluxing MeOH has been shown to lead exclusively to the formation of tetranuclear complexes [M4(L)4] , Gi - Gs (L = 1- 2 respectively) as shown in Figure 4 (36,37), Furthermore, metal salts like Ni(II)acetate, Zn(II)acetate and Cu(ll)acetate could also be used for the preparation of these complexes (Hanan, G. S. Volkmer, D. Schubert, U. S. Romero-Salguero, F. Lehn, J.-M. Baum, G. Fenske, D. to be published.). The crystalline complexes were characterized using ESI mass spectrometry, UV and IR spectroscopy, elemental analysis and NMR spectroscopy. 

A whole host of characterization techniques have been employed to assess the occurrence and the extent of the modification. These tools include FTIR and XPS spectroscopy, elemental analysis, contact angle measurements, inverse gas chromatography (IGC) and scanning electron microscopy (SEM). New emerging techniques, such as the take-off angle photoelectron spectroscopy, secondary ion mass spectrometry (SIMS), solid state NMR, confo-cal fluorescence microscopy and atomic force microscopy (AFM) have recently started to he used in this field. 

Basic analysis, including infrared spectroscopy, elemental analysis and X-ray photoelectron spectroscopy, can determine the composition, bonding and percentage of unreacted end groups. Solid-state and nuclear magnetic resonance (NMR) spectroscopy is an increasingly important technique. 

Chemical type, ionic character, viscosity, average molar mass and molar mass distribution are properties of a polymer that may be characterised. Determination of chemical type may be accomplished using a variety of techniques such as infrared spectroscopy, GC-pyrolysis, NMR and elemental analysis techniques. 

A very unusual reaction of 2-isopropyl-2-oxazoline 71 (R=H) needs mention. Nehring and Seelinge/ reported that on refluxing a 1,2-dichloroethane solution of 71 and MA, a 77% yield of the product 72 was obtained. When R = methyl, a 48% yield of a similar adduct was formed. The structure was proved by NMR, IR spectroscopy, elemental analysis, and hydrolysis studies. It is interesting to note that the hydrogen atom of the isopropyl group is so active for Michael addition, since that would be required as part of the sequence. 

The non-volatile organic portions of both skunk and mink scent were also examined. In the skunk, this portion contains mostly nitrogen-containing aromatic compounds as Judged by nmr and elemental analysis. Uv spectroscopy on substances partially purified by column and thin-layer chromatography suggested that they are mono- or di-substituted quinolines. In the mink, however, the non-volatile portion is composed of triglycerides. 

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