Syntheses and Structures of Heterobicyclic Bis(tert-butylamido)cyclodiphosph(III)azane Compounds Having Phosphorus(III) and Arsenic(III) Centers Ingo Schranz, Luke P. Grocholl, and Lothar Stahl* Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202-9024 Richard J. Staples Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 Alison Johnson Department of Chemistry, St. Cloud State University, St. Cloud, Minnesota 56301-4498 ReceiVed December 7, 1999 Syntheses and single-crystal X-ray diffraction studies of heterobicyclic cyclodiphosphazanes having central phosphorus(III) and arsenic(III) atoms are described. Interaction of PCl 3 or AsCl 3 with cis-[( t BuNP) 2 ( t BuNLi•THF) 2 ] produced the isomorphous {[( t BuNP) 2 ( t BuN) 2 ]ECl};E ) P(1), As(4), respectively. These C s -symmetric molecules crystallize with two molecules in the monoclinic space group P2 1 /m. Unit cell dimensions of 1 are (293 K) a ) 9.777(1) Å, b ) 11.745(1) Å, c ) 9.986(2) Å, and  ) 97.44(1)°; those of 4 are (213 K) a ) 9.688(3) Å, b ) 11.873(3) Å, c ) 9.975(3) Å, and  ) 97.80(3)°. When {[( t BuNP) 2 ( t BuN) 2 ]PCl} was treated with NaN 3 or LiN- (SiMe 3 ) 2 , {[( t BuNP) 2 ( t BuN) 2 ]PN 3 }(2) and {[( t BuNP) 2 ( t BuN) 2 ]PN(SiMe 3 ) 2 }(3), respectively, were obtained. Compound 2 crystallizes in the monoclinic space group P2 1 /m and has unit-cell dimensions (213 K) of a ) 9.496(7) Å, b ) 12.455(7) Å, c ) 10.043(6) Å, and  ) 97.23(4)°, Z ) 2. No congeners in the periodic table of the elements form compounds of a greater structural variety than nitrogen and phosphorus. 1 This is due in part to the ability of these nonmetals to form single, double, and triple bonds with each other. It is, however, also due to the strength of P-N bonds, which render most phosphorus-nitrogen compounds exceptionally thermally stable. While the unsaturated cyclophosphazenes and their polymeric products are the oldest and best-known class of P-N compounds, 2 the saturated phosphazanes also have a well- established chemistry. 3 We are investigating bis(amino)cyclodiphosphazanes, 4 A, as N-donor ligands for main-group and transition elements. 5 Recently we reported the syntheses of antimony(III) (5) and bismuth(III) compounds of A with intramolecular base stabiliza- tion. 6 The smaller group 15 elements are not expected to exhibit interactions with the cyclodiphosphazane ring, but they should form molecules of even greater stability. Below we describe syntheses and X-ray structures of the first fully characterized arsenic and monophosphorus derivatives of a bis(amido)- cyclodiphosphazane. Experimental Section General Considerations. All operations were performed under an atmosphere of argon or prepurified nitrogen on conventional Schlenk * Author to whom correspondence should be addressed. (1) (a) Corbridge, D. E. C. Phosphorus: An Outline of its Chemistry, Biochemistry and Technology, 5th ed.; Elsevier: Amsterdam, 1995. (b) Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements, 2nd ed.; Butterworth-Heinemann: Oxford, 1998. (2) (a) Mark, J. E.; Allcock, H. R.; West, R. Inorganic Polymers; Prentice Hall: Englewood Cliffs, NJ, 1992. (b) Neilson, R. H.; Wisian-Neilson, P. Chem. ReV. 1988, 88, 541. (c) Allen, C. E. Coord. Chem. ReV. 1994, 130, 137. (3) (a) Holmes, R. R.; Forstner, J. A. Inorg. Chem. 1963, 2, 380. (b) Hill, T. G.; Haltiwanger, R. C.; Thompson, M. L.; Katz, S. A.; Norman, A. D. Inorg. Chem. 1994, 33, 1770. (c) Scherer, O. J.; Schnabel, G. Angew. Chem., Int. Ed. Engl. 1976, 15, 772. (d) Kumaravel, S. S.; Krishnamurthy, S. S.; Cameron, T. S.; Linden, A. Inorg. Chem. 1988, 27, 4546. (e) Davies, A. R.; Dronsfield, A. T.; Haszeldine, R. N.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1973, 379. (f) Zeiss, W.; Schwarz, W.; Hess, H. Z. Naturforsch. 1980, 35b, 959. (g) Dou, D.; Duesler, E. N.; Paine, R. T. Inorg. Chem. 1999, 38, 788. (4) (a) Keat, R. In The Chemistry of Inorganic Homo- and Heterocycles; Haiduc, I., Sowerby, D. B., Eds.; Academic Press: London, 1987; Vol. 2, p 467. (b) Balakrishna, M. S.; Prakasha, T. K.; Krishnamurthy, S. S. Phosphorus Sulfur 1990, 49/50, 409-412. (c) Payne, D. S.; Mokuolu, J.; Speakman, J. C. J. Chem. Soc., Chem. Commun. 1965, 599. (d) Johnson, T. R.; Nixon, J. F. J. Chem. Soc. A. 1969, 2518. (e) King, R. B. Acc. Chem. Res. 1980, 13, 243. (f) Scherer, O. J.; Anselmann, R.; Sheldrick, W. S. J. Organomet. Chem. 1984, 263, C26. (g) Dubois, D. A.; Duesler, E. N.; Paine, R. T. Organometallics 1983, 2, 1903. (5) (a) Grocholl, L.; Stahl, L.; Staples, R. J. Chem. Commun. (Cambridge) 1997, 1465. (b) Schranz, I.; Stahl, L.; Staples, R. J. Inorg. Chem. 1998, 37, 1493. (6) Moser, D. F.; Schranz, I.; Gerrety, M. C.; Stahl, L.; Staples, R. J. J. Chem. Soc., Dalton Trans. 1999, 751. 3037 Inorg. Chem. 2000, 39, 3037-3041 10.1021/ic991405r CCC: $19.00 © 2000 American Chemical Society Published on Web 06/13/2000