81-31-2 Usage
Purification Methods
Purify violanthrene by vacuum sublimation over Cu in a muffle furnace at 450o/25mm in a CO2 atmosphere [Scholl & Meyer Chem Ber 67 1229 1934]. [Beilstein 5 I 392.] Violanthrene A (anthro[9,1,2-cde]benzo[rst]pentaphene [188-87-4] M 426.5 has m 506o. [Clar Chem Ber 76 458 1943, Beilstein 5 III 2778; Violanthrene B (violanthrone) Beilstein 7 I 466, 7 II 818, 7 III 4539.]
Check Digit Verification of cas no
The CAS Registry Mumber 81-31-2 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 8 and 1 respectively; the second part has 2 digits, 3 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 81-31:
(4*8)+(3*1)+(2*3)+(1*1)=42
42 % 10 = 2
So 81-31-2 is a valid CAS Registry Number.
InChI:InChI=1/C34H20/c1-3-7-23-19(5-1)17-21-9-11-27-28-12-10-22-18-20-6-2-4-8-24(20)26-14-16-30(34(28)32(22)26)29-15-13-25(23)31(21)33(27)29/h1-16H,17-18H2