Crystallin
e solvat
es of olanzapin
e (
1), 2-m
ethyl-4-(4-m
ethyl-1-pip
erazinyl)-10
H-thi
eno[2,3-
b][1,5]b
enzodiaz
epin
e, hav
e b
een charact
eriz
ed by an X-ray analysis and th
ermal (DSC) data. Crystallization of
1 from
ethanol giv
es a solid containing both wat
er and
ethanol mol
ecul
es; th
e solvat
e 1 · H
2O · EtOH (2:2:1) is monoclinic with th
e spac
e group
P2
1/
c and th
e unit-c
ell volum
e V = 3752.8(12) Å
3. Butan-2-ol forms with
1 solvat
e which is also a thr
ee-compon
ent phas
e,
1 · H
2O · BuOH, but its stoichiom
etry is diff
er
ent (1:1:1). Th
e spac
e group for this crystal is
P2
1/
c and th
e unit-c
ell volum
e V = 2216.5(7) Å
3. Crystallin
e olanzapin
e dichlorom
ethan
e solvat
e (2:1),
1 · CH
2Cl
2, is triclinic with th
e spac
e group
e=""mml1"">.The characteristic feature of all crystal structures is presence of a pair of olanzapine molecules which form dimer stabilized by multiple weak C–Hπ interactions between the N-methylpiperazine fragment and the phenyl / thiophene systems. Theoretical calculations have been performed indicating that the total C–Hπ binding energy is about 8 kcal mol−1. In the crystal structure, the self-assembled olanzapine molecular dimers are arranged into parallel crystal planes. Packing of the layers proceeds in two ways in which structural motives are replicated by (i) perpendicular translation forming columns, and (ii) rotation around the twofold screw axis (parallel to the layer).