INTERCALATION IN HYDROTALCITE-LIKE LAYERED ZN/AL-DOUBLE HYDROXIDES WITH NAPHTHALENEDISULPHONATES

Hydrotalcite-like layered Zn/Al-double hydroxides (Zn/Al-HTs) with one of three naphthalenedisulphonates (NijDSs) as an interlayer guest dianion, were obtained as precipitates from weak alkaline solutions of NijDS admired with calcined host powder. Two values of interplanar spacing were observed in the powder X-ray diffraction patterns of NijDS-intercalated Zn/Al-HTs with two guest isomers. Intercalated materials have been characterized by means of UV-vis diffuse reflectance spectroscopy, differential thermal ana lysis/thermogravimetry and X-ray photoelectron spectroscopy. A model has been proposed in which the organic dianion at the interlayer gallery region bridges two Al3+ cations in neighbouring layers of double hydroxides. The guest molecules have an orientation perpendicular to the internal surface of the layers for all NijDS-intercalated materials. Another orientation has been suggested in which the molecules tilt from the perpendicular position for two isomers of NijDS.