1
1+2
N
F
F
XB network 1-3
N
3 N
R R?
R
3+2
N
R2
OH
HO
OHN
R4 R3
HO
R3
HB network
R4
2a R1,R2,R3,R = H
2b R1,R2,R3H R?=F
2c R1,R2,R3.R4 = F
2a-3 R1,R2,R3,R = H
2b-3 R1,R2,R3 = H R?=F
2c-3 R1,R2,R3,R = F
Scheme 1 Synthesis of hydrogen-bonded (HB) and halogen-bonded
(XB) co-crystals. Co-crystallization of XB donor 1 or HB donor 2 with
1,2-bis(4-pyridyl)ethane 3 to form the XB network 1-3 or HB network
as 2-3, respectively.