Hydrogen bonding in thiourea: Diethyl oxalate complex in 2:1 ratio

The crystal structure of thiourea:diethyl oxalate in 2:1 ratio is the first of its kind where the diethyl oxalate exists as a solid which otherwise is a liquid at room temperature. It crystallizes in triclinic centrosymmetric space group P-1 with the following unit cell dimensions a = 7.1870(7) Å, b = 7.4890(8) Å, c = 8.3637(7) Å, α = 63.783(7)∘, β = 67.41(1)∘, γ = 64.933(7)∘. The R-factor = 0.0386 for 1850 Fo > 4σ (Fo) and 0.0417 for all 2020 data. There is a center of inversion at the center of the C–C bond of diethyl oxalate. This system is stabilized by N–H ⋅s S and N–H ⋅s O hydrogen bonds