Chem. Mater. zyxwvut 1992,4,813-818 Synthesis and Characterization of Layered Chlorocadmates(I1) with Perovskite-like Structures 813 L. P. Battaglia, A. Bonamartini Corradi, and G. Pelosi Istituto di Chimica Generale e Inorganica, Centro di Studio per la Strutturistica Diffrattometrica del C.N.R., University of Parma, 43100 Parma, Italy M. R. Cramarossa, T. Manfredini, and G. C. Pellacani* Dipartimento di Chimica, Facoltd di Ingegneria, University of Modena, 41100 Modena, Italy A. Motori, A. Saccani, and F. Sandrolini Dipartimento di Chimica Applicata e Scienza dei Materiali, Facolth di Ingegneria, University of Bologna, 40136 Bologna, Italy M. F. Brigatti Istituto di Mineralogia e Petrografia, University of Modena, 41100 Modena, Italy Received December 6, 1991. Revised Manuscript Received March 18, 1992 The synthesis and the structural, thermal, and electricalcharacterization of tetrachlorocadmate(II) zyx systems, with perovskite-like structures, are described. The countercations are diprotonated amines, such as the ethylenediamine and propane-l,&diamine dications. The structural model of the compounds consists of layers extending to the ab plane of CdC1, corner sharing octahedra. The holes between these layers are occupied by allcylammonium ions stabilizing the structure through hydrogen bonding. Thermal analysis shows the presence of a first-order phase transition in the propane-l,3-diammonium compound, related to the disordering of the hydrocarbonchains at high temperaturea which causes a decrease in the c parameter and minor differences in the a and b parameters. The electrical conductivity of the investigated compounds is apparenly protonic and seems to increase as the distance between the layers containing the inorganic chains increases. Introduction Layered silicate clays are well recognized for their ability to form a variety of pillared intercalated derivatives1p2 with novel properties for selective absorption and cataly~is.~-~ Two-dimensional polymeric chlorocadmates(I1) have re- ceived a great deal of attention from both the theoretical and experimental points of view because of their peculiar properties, such as structural, thermal, catalytic, electrical, etc., and of the prediction of impurity electronic configu- rations and their lattice locations, which is a key problem in semiconductor By analogy to the layered silicates, these chlorocadmates(I1) may also represent a potentially important class of lamellar ionic solids which give pillared derivatives. In zyxwvut this respect the Cd2+ ion, being a d10 species, is particularly suitable for designing the construction of these structural archetypes, because of its variety of coordination numbers and geometries, depending on crystal-packing, hydrogen bonding, and halide dimen- sions?Jo These materials, which present the same polarity as pillared layered silicate clays, consisting of negatively (1) Vaughan, D. E. W. Catal. Today 1988,2, 187. (2) Pinnavaia, T. Science 1983,220, 365. (3) Adams, J. M. Appl. Clay Sci. 1987,2, 309. (4) Catalysis Today-Pillared Clays; Burch, R., Ed.; Elsevier: Am- sterdam, 1988, Vol. 2, No. 2-3, pp 185-368. (5) Figueras, F. Catal. Reo. Sci. Eng. 1988, zyxwvutsrq 30, 457. (6) Mokhlisse, R.; Couzi, M.; Chanh, N. B.; Haget, Y.; Hauw, C.; Meresse, A. J. Phys. Chem. Solids 1985, 46, 187. (7) Chanh, N. B.; Hauw, C.; Merease, A.; Rey-Lafon M.; Ricard, L. J. Phys. Chem. Solids 1985,46, 1413 and references therein. (8) Bensekrane, M.; Goltzene, A.; Meyer, B.; Schwab, C.; Elwell, D.; Feigelson, R. S. J. Phys. Chem. Solids 1985, 46, 481 and references therein. (9) Dean, P. A. W. Progr. Znorg. Chem. 1978,24, 109 and references therein. (10) Tuck, D. G. Reo. Znorg. Chem. 1979,1,209 and referencea therein. 0897-47561921 28O4-0813$03.O0/0 charged CdC&-like layers separated by densely intercalated chains of organic cations, can easily afford products with tailored interlayer distances depending on the cation lengths. As such, they may find practical utilization as starting materials'l for the preparation of new pillared derivatives with gallery heights and pore sizes, such as is required for catalytic reactions of organic molecules. In the present paper we report the synthesis and the structural, thermal, and electrical characterization of tetrachlorocadmate(I1) systems having perovskite-like structures which contain diprotonated amines, such as the ethylenediamine and propane-1,3-diaminedications (enH2 and pnH2, respectively). The crystal and molecular structure of the [CdC14](pnH2) compound has been re- ported by Willett.12 The present results are compared with those previously obtained for a compound having similar structure in which the inorganic layers were sep- arated by diethylenetriamine trications (denH3).13 Further interest arises from the fact that these materials represent unusual solid inorganic/organic composites and zy can serve as a model system for understanding the factors controlling the stereochemistry and polymeric nature of the metal(I1) ion, as well as the correlations among sym- metry, thermal, optical and electrical behavior.13-15 (11) Landis, M. E.; Aufdembrink, B. A.; Chu, P.; Johnson, I. D.; Kirker, G. W.; Rubin, M. K. J. Am. Chem. SOC. 1991, 113, 3189 and references therein. (12) Willett, R. D. Acta Crystallogr. 1977, B33, 1641. (13) Manfredini, T.; Pellacani, G. C.; Battaglia, L. P.; Bonamartini Corradi, A.; Motori, A.; Sandrolini, F. Mater. Chem. Phys. 1988,20,215. (14) Manfredini, T.; Pellacani, G. C.; Battaglia, L. P.; Bonamartini Corradi, A,; Giusti, J.; Motori, A.; Saccani, A.; Sandrolini, F. Mater. Chem. Phys. 1989, 24, 215. (15) Battaglia, L. P.; Bonamartini Corradi, A.; Pepoei, G.; Cramaroeaa, M. R.; Manfredini, T.; Pellacani, G. C.; Mobri, A.; Saccani, A.; Sandrolini, F.; Giusti, J. Mater. Eng. 1990, 1, 537. 0 1992 American Chemical Society