### Abstract

The conversion of pentamer [(^{t}BuCH_{2})_{2}TaN]_{5} (2) and ammonia to cubic TaN_{0.8} (5) proceeds via precipitate 1/n[TaC_{1.41}H_{3.90}N_{1.90}]n (3) and amorphous TaN (4). Precursors other than (^{t}BuCH_{2})_{3}Ta=CH^{t}Bu (1) and NH_{3}, which provided 2, such as Ta(NMe_{2})_{5} (7) and NH_{3}, (Me_{2}N)_{3}-Ta=N^{t}Bu (9) and NH_{3}, also afforded 5. Extended Hückel molecular orbital calculations were conducted to examine the electronic changes that appear upon oligomerization of hypothetical Me_{2}TaN to (Me_{2}TaN)_{∞}, as a model for pentamer 2 formation. The relationship between pentamer 2 and the remaining nitrides, 3-5 was probed via magic angle spinning (MAS) and spin-echo solid-state ^{15}N NMR experiments that probe the local environments of the various nitrogen atoms. In combination with ^{15}N-labeling studies, the spin-echo spectra were used in an effort to analyze the possibility of a direct relationship between the 2-dimensional Ta_{2}N_{2} "squares" of the pentamer (2) and the 3-dimensional Ta_{4}N_{4} "cubes" of the ultimate product, cubic TaN_{0.8} (5).

Original language | English |
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Pages (from-to) | 2468-2480 |

Number of pages | 13 |

Journal | Chemistry of Materials |

Volume | 8 |

Issue number | 10 |

Publication status | Published - 1 Oct 1996 |

Externally published | Yes |

## Cite this

^{t}BuCH

_{2})

_{2}TaN]

_{5}to Cubic TaN: Related Syntheses, EHMO Calculations, and MAS and Spin Echo

^{15}N NMR Spectroscopies.

*Chemistry of Materials*,

*8*(10), 2468-2480.