[ 83-74-9] M 300.3, m 152-153 , [ ?] ²⁰ _D -54 (EtOH), pK 8.1 (80% aq MeOCH ₂CH ₂OH). Crystd from aqueous EtOH and sublimes at 150 /0.01mm.

Imidazole (glyoxaline) [ 288-32-4] M 68.1, m 89.5-9.1 , b 256 , pK ²⁵ ₁ 6.99, pK ²⁵ ₂ 14.44. Crystd from ^*benzene, CCl ₄, CH ₂Cl ₂, EtOH, per ether, acetone/pet ether and distd deionized water. Dried at 40 under vacuum over P ₂O ₅. Distd at low pressure. Also purified by sublimation or by zone melting. [Caswell and Spiro J Am Chem Soc 108 6470 1986.] ¹⁵N-imidazole was crystd from ^*benzene [Scholes et al. J Am Chem Soc 108 1660 1986].

4 ?-(Imidazol-1-yl)acetophenone [ 10041-06-2] M 186.2, m 104-107 , pK 4.54. Twice recrystd from CH ₂Cl ₂/hexane [Collman et al. J Am Chem Soc 108 2588 1986].

Iminodiacetic acid [ 142-73-4] M 133.1, m 225 (dec), pK ²⁵ ₁ 2.50, pK ²⁵ ₂ 9.40. Crystd from water.

1,3-Indandione [ 606-23-5] M 146.2, m 129-132 , pK ¹⁸ 7.2 (1% aq EtOH). Recrystd from EtOH [Bernasconi and Paschalis J Am Chem Soc 108 2969 1986].

Indane [ 496-11-7] M 118.1, b 177 , d 0.960, n 1.538. Shaken with conc H ₂SO ₄, then water, dried...