Merck Phase

Fig. 13a-c. EPR spectra of Cu(TPP) diluted into a frozen nematic glass at 10 K (Merck Phase 5). a) Unoriented sample, b) Frozen nematic glass, oriented along B0 (B0 in the complex C plane), c) Frozen nematic glass, rotated by 90°. (Ref. [84])... 

Fig. 18 a, b. DOUBLE ENDOR spectrum of Cu(TPP) in a frozen nematic glass (Merck Phase 5). a) Two-dimensional nitrogen ENDOR spectrum with B0 in the complex plane. ENDOR observer frequency (v = 19 MHz) used in b) is marked by an arrow, b) DOUBLE ENDOR spectrum the corresponding ENDOR frequencies cN( 1/2) = AJ72 3/2 Qj vN obtained from single crystal work1 are marked by arrows. (Ref. 84)... 

Figure 6.10. Effect of polarized light on oriented DHI 34/LC (nematic) assemblies. Ey is the extinction when the polarized light is parallel to the electric vector of the light (Ei perpendicular). Molecules were oriented mechanically in the nematic phase. E or T refers to the extinction measured for 34 or 46 with parallel (or perpendicular) light in the nematic ZLI-2452 (Merck) phase (Type I).

In almost all the measurements the standard reference material 4-methoxybenzyli-dene-4 -n-butyl-aniline (MBBA) or a mixture, Merck Phase V, have been used, sometimes doped with an ionic substance. MBBA is the only room-temperature nematic with dielectric anisotropy < 0 where all the material parameters have been measured. For tabulated values see e.g. Ref. [12]. Unfortunately, it is a Schiffbase and rather imstable when exposed to moisture. Therefore, it is difficult to control the long-time conductivity in situ. Thus the recent successful introduction of the very stable material 4-ethyl-2-fluoro-4 -[2-(rrani-4-n-pentylcyclohexyl)-ethyl]-biphenyl (152) doped with iodine is very promising [50, 51]. This material exhibits at low external frequencies strongly oblique travelling rolls which bifurcate supercritically, leading to a particularly interesting scenario. ... 

In any case, if decreasing the external frequency the LP on the neutral curve typically moves down and may eventually cross the minimum at qc leading to oblique rolls at threshold. This is the case for the materials Merck Phase V and 152. Then, simultaneously moves down to zero. Of course shifts of Szz and the LP on the neutral curve can also be effected by changing the material parameters. Figures 13.9a,b give an impression of the de-... 

Recently most material parameters of Merck Phase V have been measured, see note added at the end. The material parameters of 152 have either been measured directly or fitted to EHC measurements [49]. 

BBT solution on unmodified sorbents of different nature was studied. Silica gel Merck 60 (SG) was chosen for further investigations. BBT immobilization on SG was realized by adsoi ption from chloroform-hexane solution (1 10) in batch mode. The isotherm of BBT adsoi ption can be referred to H3-type. Interaction of Co(II), Cu(II), Cd(II), Ni(II), Zn(II) ions with immobilized BBT has been studied in batch mode as a function of pH of solution, time of phase contact and concentration of metals in solution. In the presence of sodium citrate absorbance (at X = 620 nm) of immobilized BBT grows with the increase of Cd(II) concentration in solution. No interference was observed from Zn(II), Pb(II), Cu(II), Ni(II), Co(II) and macrocomponents of natural waters. This was assumed as a basis of soi ption-spectroscopic and visual test determination of Cd(II). Heavy metals eluted from BBT-SG easily and quantitatively with a small volume of HNO -ethanol mixture. This became a basis of soi ption-atomic-absoi ption determination of the total concentration of heavy metals in natural objects. 

HPTLC plates Cellulose (Merck). The plates were prewashed with mobile phase and dried for 10 min in a stream of warm air before use. 

HPTLC plates Sihca gel 60 (Merck). Before apphcation of the samples the layer was prewashed once with the mobile phase and dried at 110°C for 20 min. Before it was placed in the developing chamber the prepared HPTLC plate was preconditioned for 30 min at 0% relative humidity (over cone, sulfuric acid). 

MK-677, an orally active spiroindoline-based growth hormone secretagogue (GHS) agonist, discovered by Merck and currently in Phase II clinical studies, was synthesized with a Fischer indolization as a key step. The synthesis of this agonist involved a Fischer indole/reduction process and was achieved in 48% overall yield from the relatively cheap starting material, isonipecotic acid 72. ... 

Fig. 7-9. Separation of amino acids after derivatization 5 with OPA and mercaptoethanol. Column Superspher 100 RP-18 (4 pm) LiChroCART 250-4, mobile phase 50 mM sodium acetate buffer pH 7.0/methanol, flowrate 1.0 ml min temperature 40 °C detection fluorescence, excitation 340 nm/emission 445 nm. Sample amino acid standard sample (Merck KGaA Application note W219180).

A precursor in the synthesis of a promising calcium sensitizing agent from E. Merck [33], a chiral thiadiazin-2-one EMD 53986, 3,6-Dihydro-5-[l,2,3,4-tetrahy-dro-6-quinolyl]-6-methyl-2H-l,3,4-thiadiazin-2-one [26]. The study was performed using Celluspher , a CSP prepared from cellulose tri(p-methylbenzoate) according to a patent from Ciba-Geigy [34]. The spherical particles had a mean particle diameter of 20 3 pm and the mobile phase was pure methanol. 

Note Under the conditions employed emetine and cephaeline were not well separated but there was good resolution of the subsidiary alkaloids of the ipecacuanha tincture (Fig. 1). The separation and quantitative determination of the main alkaloids (Fig. 2) can be carried out under the following conditions Ascending, one-dimensional development in a trough chamber with chamber saturation layer HPTLC plates Silica gel 60 (Merck) mobile phase dichloromethane — methanol — ammonia solution (25%) (34+6+1) migration distance 6 cm running time 13 min h/ f cephaeline 65-70 emetine 75-80. 

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