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 nanocomposite hybrid materials are composed of two-dimensional MQ (II-VI) slabs and organic bifunctional molecules that act as links as well as spacers. The most intriguing properties of these nanostructures are that they exhibit strong quantum confinement effect while possessing a perfectly periodic arrangement. The crystal structures of [MnSe(en)(0.5)] (1; en = ethylenediamine), [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 in orthorhombic crystal system, space group Pbca (No. 61), Z = 4. Crystal data 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 isostructural 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) Angstrom. 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 compounds are thermally stable up to 250 degreesC.