Hydrogen-bonded networks formed by substituted 2,6-diarylpyrazines

The X-ray crystal structure of 2,6-bis(4\u27-hydroxyphenyl)pyrazine and 2,6-bis(4\u27carboxyphenyl)pyrazine are reported. The structure of the 2,6-bis(4\u27-carboxyphenyl) pyrazine dimethylsulfoxide complex (C18H12N2O4)⋅(C2H6OS) is triclinic, P-1, with a = 7.9933(8), b = 10.7165(10), c = 12.1337(12) Å, α = 66.385(2), β = 84.070(2), γ = 77.219(2)∘. The structure comprises stacked two-dimensional sheets of the hydrogen bonded complex. The two-dimensional sheets comprise hydrogen-bonded ribbons of the (carboxyphenyl)pyrazine that are connected by bridging hydrogen bonds to the dimethylsulfoxide. The structure of 2,6-bis(4\u27-hydroxyphenyl)pyrazine, C16H12N2O2, is monoclinic, P21/c, with a = 10.6107(13) Å, b = 14.6743(18) Å, c = 8.3772(10) Å and β = 104.982(2)∘. The structure reveals that two-dimensional hydrogen-bonded sheets are formed with pyrazine–phenol and phenol–phenol hydrogen bonds