CRYSTAL ~~ORPHOLOGY Crystal System. Monoclinic. Form and Habit. Tablets lying on the basal pinacoid { 001 ] elongated parallel to b showing the ortho pinacoid { l o o ) , the hemiorthodome and the prisms { 1101, {210},and 1310). Axial Ratio. a:b:c = 3.198: 1: 1.351. Interfacial Angles (Polar). 901 A001 = 310 810 = 86'20' .~ A 5105&l' (projection on 100) 310 A 3l,0 = 210 A 210 = 64'20' 95'&6 (projection on 100) 210A210 = 110 A 110 = 35"30' 72'4_8' (projection on 100) 110 A 110 =
OPTICALPROPERTIES Refractive Indices (5893 A , ; 26' C.). cy = 1.532 rt 0.002; p = 1.59 i 0.01; y =>2.0. Optic Axial Angles (5893 A.; 25' C.). 2 E = 74'; 2V = 45". Dispersion. r > u. Optic Axial Plane. y d c = 7" in obtdse p. Sign of Double Refraction. Posit'ive. Atute Bisectrix. y . Extinction. p A a = 25' in obtuse p. Molecular Refraction ( R ) (5893 A.; 25" C,). qi/cypy = 1.700. R(ca1cd.) = 45.63; R(ohsd.) = 47.7. FUSION DATA. PDMAB sublimes on heating, the condensate forming as droplets; final melting occurs a t 72.1' C. The refractive index of the melt is 1.6128 at 99-101' C. and 1.6229 a t 82-4' C. ; the resulting temperature
pol},
40'28'
Beta Angle. 122'. X-RAYDIFFRACTION DAT.4 Cell Dimensions. a = 24.43 A.; b = 7.64 A.; c = 10.32 A.
NICHOLSON, Humble O i l and Refining Co., Baytown, Tex.
x or v B. 1. Pts.
1
2
Ij
5,5-Dimethyl4-ethyl-3. :;-hex-
CSH180S
4,6,6-Trimethyl-3thia-2-hep1 tanone
CsHisOS
0-100
12
1
1I
1
Slit
CS-81
(mm) AX or
Concn. mg/ml length
Av
mm
I
Component Range ~
%
racy ~
%
1
8 . 1. Pts.
Slit (mm)
''
AXor
Av
I
Concn. mglml length mm.
Pentamethyldiphenylmethane
I
~
I 1 ~~
Base l i n e - X
1
methyldiphenylethane
0.085~ 1.00
~~
PointInstrument: Perkin-Elmer Model 21, NaCl prism Sample Phase: Solution in carbon disulfide
Successive approx.--
Cell Windows: NaCl Absorbonce Measurement:
Relofive Absorbances"-Analytical Matrix:
12.30~ 0.630
1
Formuh
or v
I
I
ComponentfX
1
Name
I
x
diphenyl (bimesityl)
1
I
0-100
Inverse matrixGraphical&
1
I
No.1
Instrument: Perkin-Elmer Model 21, NaCl prism Sample Phase: Liquid mixtures, without solvent
Calculation:
ACW-
!
1
,
CS-82
D. E. NICHOLSON, Humble O i l and Refining Co., Baytown, Tex.
12.30 0.224 0.044~ 0.092
I
Cell Windows: NaCl Absorbance Meosuremenf:
Ill.
Determination of Diphenyls Related to 1,3,5-Trirnethylbenzene
Determination of Isomeric Thiolacetates in Binary Mixtures D. E.
coefficient of refractive index is 0.00058. On cooling, the melt tends to supercool; however, recrystallization is spontaneous. The rate of growth is rapid and increases as cooling continues. The crystals formed from the melt are coarse-grained spherulites. On a meltback, well-formed crystals are formed. The crystals are tablets lying on 001 and are elongated parallel to b. An off-centered biaxial, positive interference figure is obtained showing an optic axial angle, 2E, equal to 74'. The crystals show high birefringence with normal polarization colors. The growing edge shows a-ell-formed prisms 110, 210, 310. Shrinkage cracks are evident running parallel to a. PDAfAB forms eutectics with azobenzene and benzil with eutectic temperatures of 42-3' and 50.0-0.5" C., respectively; the benzil-PDJZAB eutectic contains 55 zt 1% PDMAB. COSTRIBUTIOXS of crystallographic data for this section should be sent to Kalter C. McCrone, 501 East 32nd St., Chicago 16,
'Formula Weights per Cell. 8 (7.961 calculated from x-ray data). Formula Weight. 149.19. Density. 1.210 (flotation and pycnometer); 1.216 (x-ray).
fidence in the values obtained. The authors would welcome any suggestions as to methods of checking directly the beta and gamma values obtained.
Moferiol Purity: Component 2, 98%; component 1, 50% taminant being component 2.
Colcubtion:
with the con-
Comments: Alternate nomenclature for components; No. 1: 1,3,3trimethylbutyl thiolacetate; No. 2: 2,2-dimethyl-1 -ethylpropyl thiolacetate; Component 2 was determined b y difference.
Inverse matrixGra p hica I-.-.-.-
Point& Successive a p p r o x . - X
Relative Absorbancesa-Anolyficol Mofrix: ComponentlX 9.96~
1 2 3 Moferial Purify:
Relative absorbances are given as the slope of the Beer's law concentration curves used expressed in terms of absorbance per 100% of constituent.
Base line-
0.0378 0.0093 0.0069
12.04~ 0.0043 0.0481 0.0203
14.38~ 0.0037 0.0054 0.0715
Synthesized compounds of approximately 97% purity
Relative absorbances are given as the slope of the Beer's law concentration curves used expressed in terms of absorbance per lOOYc of constituent.
~~~
These d a t a represent standard publication a n d submission is open t o anyone in accordance with regulations of ANALYTICAL CHEM\IIBTRY. T h e Coblentr Societv is acting only a s a n aid t o t h e journal.
1 120
ANALYTICAL CHEMISTRY
To standardize procedure AXALYTICAL CHEMISTRY r e q ~ ~ e s t hs a t material be sent in quintuplicate t o t h e chairman of the review committee: Robert C. Wilkerson, Celanese Corp. of America, Post Office Box 8, Clarkmood, Tex.
