4-ethyl- tetraphenylborate

Solid-phase microextraction capillary gas chromatography (SPME-GC) is also an interesting preconcentration method. After derivatization with tetraethylborate, tetrapropylborate, or tetraphenylborate, the ethylated compounds are extracted by SPME on a silica fiber coated with polydimeth-ylsiloxane (PDMS). SPME can be performed either in the aqueous phase or in the headspace. After SPME extraction, species are thermally desorbed, separated by GC, and analyzed.106... 

Dimethyl Phenyl Telluronium Tetraphenylborate1 0.46 g (2 mmol) of dimethyl telluronium dichloride are dissolved in 30 ml of absolute methanol and a solution of 1.7 g (5 mmol) of sodium tetraphenylborate in 30 ml of methanol is added dropwise with stirring at 20°. Stirring is continued for 2 h, the mixture is filtered, and the solid is recrystallized from ethyl methyl ketone yield 0,81 g (65%) decomposes above 200°. 

Introduction to Derivatization For many years derivatization by alkylation -especially as ethylation, but also as propylation - has been applied to transform Hg species into volatile Hg species before measurement with hyphenated techniques [2, 50, 52]. Sodium tetraphenylborate (NaBPh4) was also used for derivatization prior to measurement with GC-MIP-AED [53], Studies of possible species transformation, for example, during the analytical procedure, have been carried out with isotope-specific determination methods. The results showed that a direct ethylation of Me-Hg in an atmospheric precipitation sample by NaBEt4 produced no significant amount of artifactual Me-Hg [54]. Others investigated the species transformation processes in synthetic solutions to simulate environmental matrices. From the experiments it could be concluded that the species conversion, for example, of Me-Hg into zerovalent Hg, depends on the concentration levels of the halide [2]. Furthermore, the procedural order is of great importance, for example, ethylation should be done after addition of the organic phase to avoid species transformation [55]. 

Linear single bridges have been found in the structures of /i-iodo-bis[tris(2-diphenylarsino-ethyl)aminenickel(I)] tetraphenylborate and i-iodo-bis[tetrakis(phenyl isocyanide)iodocobalt(II)] iodide. In both cases the metal to bridging iodide distance is long (Ni—12.994 A, Co—12.891 A) and this is rationalized in terms of the steric requirements of the phenyl rings on the ligands. 

Elliptinium, the 2-methyl derivative of 9-hydroxyellipticine (Figure 6.11) has been measured in plasma using an ODS-modified silica column and methanol-water (60-1-40) containing ammonium acetate (100 mmol L final pH 6.0) as eluent. Sample preparation was by ion-pair extraction into ethyl acetate containing sodium tetraphenylborate. The 2-propyl homologue was used as the internal standard. Detection was at a GCE (0.6 V V5 Ag/AgCl). The LoD was 250 pg (S/N = 2), equivalent to 25 pgL for a 200 pL sample. 

The reaction was extensively stndied for cinnamyl esters (acetate and carbonate) as allylic snbstrates, with some examples given for allyl acetate and its homologues, and a wide range of nncleophiles inclnding N-nucleophiles (primary and secondary amines, hydroxylamine and its derivatives, and sodium azide), C-nucleophiles (malonates, ethyl acetoacetate, acetylacetone, sodium tetraphenylborate), and S-nucleophile sodium p-toluenesuhinate. 

Cs 1H4 5Cli,N3P2Pt, cis-Chlorobis( triphenylphosphine) - (1,3-di-p-tolyl-triazenido)platinum(II) chloroform solvate, 42B, 874 Cs1H4 5N3OP2RU, Hydrido(1,3-di-p-tolyltriazenido)bis(triphenylphos-phine)ruthenium(II) carbonyl, 42B, 874 Cs iHi, 9BF N2P2Pt, trans Hydrido(acetone phenylhydrazone)bis(triphen-ylphosphine)platinum(lI) tetrafluoroborate benzene, 43B, 1343 CsiH62AsBNnNiS, Isothiocyanato-(N,N-bis-(2-(diethylamino)ethyl)-2-(diphenylarsino)ethylamine-N,N,N)-nickel(II) tetraphenylborate,... 

Cg gHg 2BC0N3O3P3, Dinitrosyl(bis-(2-diphenylphosphinoethyl)-2-diphen-ylphosphineoxide-ethyl)aminecobalt tetraphenylborate, 41B, 1223 Cs sHe 2BFeNOPi, Nitrosyltr is-(2-dipheny Iphosphinoethyl jphosphineiron tetraphenylborate, 41B, 1224... 

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