CRYSTAL ENGINEERING OF STACKED AROMATIC COLUMNS - 3-DIMENSIONAL CONTROL OF THE ALIGNMENT OF ORTHOGONAL AROMATIC TRIADS AND GUEST QUINONES VIA SELF-ASSEMBLY OF HYDROGEN-BONDED NETWORKS

We here determined the crystal structures of several adducts of the bi s(resorcinol) and bis(pyrimidine) derivatives of anthracene or anthraq uinone (1-3) as orthogonal aromatic triads. Anthracene-bis(resorcinol) compound 1 forms molecular sheets consisting of hydrogen-bonded homop olymeric chains of resorcinol together with anthracene stack columns h aving a face-to-face distance of I-a-a(f) = 12.0-13.4 Angstrom; large supramolecular cavities left are occupied by two solvent molecules as guests via hydrogen bonding. Cocrystallization of compound 1 with anth racene-bis-(pyrimidine) derivative 2 affords adduct 1.2, whose molecul ar sheets are composed of hydrogen-bonded resorcinol-pyrimidine altern ate copolymeric chains and closer anthracene columns with I-a-a(f) = 8 .40 or 8.49 Angstrom. Columns in neighboring sheets are in a close pro ximity or even partially overlapped as a result of interpenetration of the sheets. Compound 1 also forms a 1:1 adduct with anthraquinone-bis( pyrimidine) derivative 3. The resulting adduct 1.3 exclusively forms a resorcinol-pyrimidine O-H ... N hydrogen-bonded network as above but in a different way. The resulting sheets are layered so as to give seg regated columns of anthracene (I-a-a(f) = 11.78 Angstrom) and anthraqu inone (I-q-q(f) = 10.56 Angstrom) which are partially overlapped with each other. Compound 1 and quinone form 1:2 (1 to quinone) adducts. An extensive 1-quinone hydrogen-bonded network in the benzoquinone adduc t leads to 3-fold interpenetrating or polycatenating molecular sheets having highly slided anthracene columns (I-a-a(f), = 3.99 Angstrom) an d quinone columns (I-q-q(f) = 2.87 Angstrom). The anthraquinone adduct , on the other hand, forms hydrogen-bonded one-dimensional alternate c hains composed of 1 and face-to-face stacked quinone dimer. These chai ns are so arranged as to give segregated and partially overlapped colu mns for anthracene (I-a-a(f) = 5.24 Angstrom) and anthraquinone (I-q-q (f) = 3.03 or 3.55 Angstrom). It is remarkable that many of the column s are constructed via self-assembly of hydrogen-bonded one-dimensional (1D) or two-dimensional (2D) networks. The network-self-assembly stra tegy thus opens the door to a three-dimensional (3D) control of aromat ic columns in molecular crystals, i.e., co-alignment in proximity of d onor columns and acceptor columns.