Crystal Forms of the Antiepileptic Lamotrigine: Molecular Salts and Solvates with Fluorobenzoic Acid,Nicotinic Acid, 2-Thiobarbituric Acid, 3-Picoline and Butyl Alcohol

Abstract  

The crystal structures of three salts and two solvated multicomponent crystals of lamotrigine with 4-fluorobenzoic acid, nicotinic acid, 2-thiobarbituric acid, 3-picoline and butyl alcohol are reported. Compound 1a crystallizes in monoclinc system, space group P2₁ with a = 13.3860(5) ?, b = 8.3420(3) ?, c = 15.5200(6) ?, β = 93.524(1)°, V = 1729.78(11) ?³, and Z = 2. Compound 1b crystallizes in monoclinic system, space group P2₁/c with a = 10.6625(7) ?, b = 16.2575(11) ?, c = 13.6346(9) ?, β = 100.904(1)°, V = 2320.8(3) ?³, and Z = 4. Compound 1c crystallizes in triclinic system, space group P[`1] overline{1} , with a = 10.1309(7) ?, b = 12.0260(8) ?, c = 14.0826(10) ?, α = 71.783(1)°, β = 86.451(1)°, γ = 80.902(1)°, V = 1609.10(19) ?<sup>3</sup>, and Z = 1. Compound 1d crystallizes in monoclinic system, space group P2<sub>1</sub>/c with a = 14.9570(10) ?, b = 8.0230(6) ?, c = 13.8162(10) ?, β = 102.884(1)°, V = 1616.2(2) ?<sup>3</sup>, and Z = 4. Compound 1e crystallizes in triclinic system, space group P[`1] overline{1} , with a = 7.5710(6) ?, b = 8.5721(7) ?, c = 13.5532(11) ?, α = 85.364(1)°, β = 79.632(1) (1)°, γ = 86.188(1)°, V = 861.19(12) ?³, and Z = 2. Characteristic R₂²(8) dimer is observed in all five structures. A complete hydrogen bonded motif analysis is described. Lamotrigine-lamotrigine base pair is observed in all the structures, except in (1b). In (1c), the R₂²(7) dimer is noticed while, in all other structures R₂²(8) dimer exist between the lamotrigine-lamotrigine base pair. In all the six structures, chlorine atoms of the lamotrigine molecules are not involved in any interactions.