Needle crystal

The reaction of a mixture of 1,5,9-cyclododecatriene (CDT), nickel acetylacetonate [3264-82-2], and diethylethoxyalurninum in ether gives red, air-sensitive, needle crystals of (CDT)Ni [12126-69-1] (66). Crystallographic studies indicate that the nickel atom is located in the center of the 12-membered ring of (CDT)Ni (104). The latter reacts readily with 1,5-cyclooctadiene (COD) to yield bis(COD) nickel [1295-35-8] which has yellow crystals and is fairly air stable, mp 142°C (dec) (20). Bis(COD)nickel also can be prepared by the reaction of 1,5-COD, triethylaluminum, and nickel acetylacetonate. 

C), the yield of more than 90% purity L-glutamic acid crystals is very high. The glutamic acid crystals appear as both the metastable a- and stable P-forms. The a-form consists of prismatic crystals which are easy to filter, whereas the P-form needle crystals are difficult to filter. Control of crystallisation conditions of a-crystals are requited (13). The cmde L-glutamic acid crystals are suspended ia water and neutralized with caustic soda or sodium hydroxide. The solution is decolorized with activated carbon to produce a transparent solution and MSG is crystallized under reduced pressure. 

Eq. (87) really describes a needle crystal which, without noise, has no side branches. The corresponding star structure then cannot fill the space with constant density and the amount of material solidified in parabolic form increases with time, only fike rather than like P for a truly compact (initially finite) object in two dimensions. 

A mixture of 4.0 grams of N-methyl-3-toluidine and 2.8 grams of sodium hydrogencarbon-ate in 50 cc of acetone was stirred at 0° to 10°C and 7.4 grams of 2-naphthyl chlorothiono-formate was added in small portions thereto and the mixture was heated under reflux for 30 minutes. The cooled mixture was poured into about 150 cc of cold water and 2-naphthvl-N-methvl-N-(3-tolyl)thionocarbamate was obtained as white crystals. Yield is 9.1 grams (90 o). Recrystallization from alcohol gave colorless needle crystals, MP 110.5° to 111.5°C. 

In the case of the trans-complex, only the two chloride ions are substituted, the trans-effect of ammonia being too low to give substitution with the result that white needle crystals of trans-[Pt(NH3)2(tu)2]Cl2 are formed [73],... 

For the compound CB07 four different solid phases were found. The crystal structures of the needle and the square plate crystals were described by Hori et al. [55, 56]. The needle crystal contains two crystallographically independent molecules. The close contacts of the cyano groups of the molecules 1 and 2 form a dimeric arrangement with cyano-cyano distances of 3.52 A Nlcyano-... 

Hydroxyl IMI (0.3 g) was added to 350 mL distilled water and heated to 80 °C to obtain a solution. Hydrochloric acid (5 mL) was added and the solution heated at 80 °C for 35 min. After coohng to room temperature, the reaction solution was extracted with ethyl acetate (350 mL). The extracts were dried with 5 g anhydrous sodium sulfate and concentrated in a vacuum rotary evaporator until the product appeared as white needle crystals. The crystals were collected and dried in air (0.1 g). 

Bronner sacid orgchem C oH6(NH2)S03H Acoioriess, water-soluble naphthylamlne sulfonic acid that forms needle crystals used in dyes. Also spelled Broenner s acid. bren-orz as-od ... 

Reaction of phenylacetylene with Te/KOH/SnCf A mixtnre of 6.4 g of tellurium, 42 g of potassium hydroxide, 22.6 g of SnCl2 2H20, 10.2 g of phenylacetylene, 20 mL of toluene, 60 mL of water and 1.2 g of Adogen 464 was heated (80-97°C) with vigorous stirring for 7 h. The organic layer was separated, and the aqneons layer was extracted with benzene. The benzene was removed under vacnnm. The residne was dissolved in a small amount of ether, poured into 200 mL of isopropyl alcohol, and placed in the refrigerator for 3 days. The yellow crystals of distyryl telluride (2.5 g, yield 15%) and the red needle crystals of distyryl ditelluride (0.7 g, yield 6%) were separated. 

Fia 6 Effect of A on shock sensitivity of various explosives. NQ-f is low-bulk-density nitroguanidine with hollow-needle crystals of about 5 n diam X 60-65 it long. NQ-h is the high-bulk-density material made up of solid particles of about GO-65 n diam. DATB, TNT, and Tetryl are, respectively, dia-minotrinitrobenzene, trinitrotoluene and trinitro-phenylmethylnitramine. RDX is cyclotrimethyl-enetrinitramine which contains 2.5% lubricant. Measurements were carried out with a standardized test (Ref 16) in which a 3.65-cm-diam test explosive confined in 0.55-cm-thick steel is the acceptor and polymethyl methacrylate is the gap material MGl = NCro filt ro uasiM i ... 

Figure 4.9. Scanning electron microscope photographs showing the roughening transition of 111) faces of a TiOj crystal and the formation of hollowed needle crystals as impurities are added [19]. Growth occurs by liquid phase epitaxy on a (001) substrate. Fe203 is added as an impurity in the following amounts (a) 0%. (b) 1.3 mol%,...

Crossed lamellar structure aragonite needle crystals align in the c-axis direction forming rectangular blocks. The c-axes are inclined at 45 — 55° to the inner surface of the shell, and the neighboring blocks are oppositely inclined. 

Complex crossed lamellar structure a layer consisting of aragonite needle crystals with orientations inclined at 45° to the inner portion of the cell. These needle crystals aggregate in a radial manner, forming a conical body, which is arranged nearly perpendicularly to the inner surface of the shell. 

Composite prismatic structure the c-axis of rhombic prisms align parallel to the shell. The rhombic prism is an aggregation of aragonite needle crystals aligned in conical form in its elongation direction. 

The complex c/.s-[Pt(Me2SO)2Cl2] is obtained as pale-yellow needle crystals. It is soluble in dimethylsulfoxide and slightly soluble in chloroform and dichloromethane. Two Pt-Cl stretching vibrations occur at 334 and 309 cm-1 in nujol mulls. The S-O stretching vibrations are observable at 1157 and 1134 cm-1 in nujol mulls.7... 

Gas-chromatographic analysis (column PEG-6000, 2 meters, column temperature 180°C., carrier gas, He) of the residue showed that it consisted of three main products. The first peak was identified as bicyclohexyl, the second as 3-cyclohexylcyclohexene, and the third as 3,3 -bicy-clohexenyl. The residue was distilled, and a fraction boiling at 90°-122°C./20 mm. Hg was collected. This fraction was poured into 10 times its volume of acetic acid. The solution was cooled to 0°C., and bromine was added. Colorless needle crystals and a red viscous oily liquid were obtained. The crystalline material was recrystallized from acetic acid and melted at 157.5°-160°C. (decomp.) [literature, 158°C. (6)]. A mixed melting point with an authetic tetrabromide of 3,3 -bicyclohexenyl was not depressed. 

Examples of this extreme stereoselectivity and specificity have been found by Scheffer and Trotter in crystals of a-adamantyl p-chloroacetophenone (86b), also [282], Figure 49 shows ORTEP-like drawings of the conformations in the dimorph plate and dimorph needle crystals of 86b as obtained upon recrystallization from different solvents. A major difference between the two is the cant of the aryl ring (and the carbonyl group) with respect to the adamantyl moiety. 

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