Self-assembly via (N· · ·I) non-covalent bonds between 1,4-diiodo-tetrafluoro-benzene and a tetra-imino ferrocenophane

The tetra-imino ferrocenophane (1) was cocrystallized with 1,4-diiodo-tetrafluoro-benzene (TFDIB). In the resulting compound 2, two of the four ferrocenophane nitrogens show interactions with the iodine atoms of TFDIB leading to a polymeric structure with extended linear alternating electron donor (1) and acceptor (TFDIB) molecule chains. For the first time, imino nitrogens are involved in this type of halogen bonding. The N· · ·I non-covalent bonds (N· · ·I distances 2.879(5) and 2.896(5) A ° ; N· · ·I–C angles 171.1(2) and 178.1(2)8) are the directing interactions responsible for the observed self-assembly. The ferrocene fragments of the macrocycle are in an almost perpendicular conformation. Mo¨ssbauer spectroscopy indicates the sole presence of low spin iron (II). The temperature dependence of the magnetic susceptibility is corresponding to a quasi-diamagnetic compound. q 2003 Elsevier B.V. All rights reserved