Inorganic-organic hybrid composites containing MQ (II-VI) slabs: A new class of nanostructures with strong quantum confinement and periodic arrangement

A new class of nanostructures has been prepared and characterized. These na nocomposite hybrid materials are composed of two-dimensional MQ (II-VI) sla bs and organic bifunctional molecules that act as links as well as spacers. The most intriguing properties of these nanostructures are that they exhib it strong quantum confinement effect while possessing a perfectly periodic arrangement. The crystal structures of [MnSe(en)(0.5)] (1; en = ethylenedia mine), [MnSe(pda)(0.5)] (2; pda = propanediamine), [ZnSe(en)(0.5)] (3), and [ZnSe(pda)(0.5)] (4) have been analyzed by single crystal and powder X-ray diffraction methods. Compounds 1 and 3 are isostructural and crystallize i n orthorhombic crystal system, space group Pbca (No. 61), Z = 4. Crystal da ta for 1: a = 6.711(1), b = 6.614(1), c = 17.720(4) Angstrom, For 3: a = 6. 6326(7), b = 6.4630(6), c = 17.3540(16) Angstrom. Compounds 2 and 4 are iso structural and crystallize in orthorhombic crystal system, space group Cmc2 (1) (No. 36), Z = 4. Crystal data for 2: a = 20.384(4), b = 6.719(1), c = 6 .565(1) Angstrom. For 4: a = 19.9731(18), b = 6.6268(7), c = 6.4394(6) Angs trom. The optical absorption experiments show that both 3 and 4 generate a very large blue shift in the absorption edge (1.4-1.5 eV), and both compoun ds are thermally stable up to 250 degreesC.