1 Nitrogen–Carbon Bond Formation from N 2 and CO 2 Promoted by a Hafnocene Dinitrogen Complex Yields a Substituted Hydrazine Wesley H. Bernskoetter, Emil Lobkovsky, and Paul J. Chirik* Angew. Chem. Int. Ed. 2006, 45, 1-5

2 Chem. Commun. 2003, 2050 Carbon-Nitrogen Bond Formation

3 The Synthesis of Ammonia: Haber-Bosch Process

4 Dinitrogen Hydrogenation J. Am. Chem. Soc. 2004, 126, 14326-14327

5 J. Am. Chem. Soc. 2005, 127, 7901

6 Organometallics 2006, 25, 1021-1027 Preparation of 1-N 2

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8 J. Am. Chem. Soc. 2006, 128, 10696

9 13 C NMR:δ 155.77 (d, 14.6Hz, 15 NCO 2 ) 15 N NMR: δ184.0 (d, 13.1Hz), 319.6 (d, 13.1Hz).

10 The N1–N2 bond length of 1.471(7) Å C37–O1 and C38–O3 : 1.323(7) and 1.303(8) Å C37–O2 and C38–O4 : 1.208(8) and 1.228(8) Å bond orderd(N-N)/A 10 10 3 (N 2 )1.0976 2 (N 2 Me 2 )1.23 1 (N 2 H 4 )1.454 http://www.geocities.com/Vienna/Strasse/6671/n2/n2.html

11 30% 15% 13 C and 15 N NMR resonances centered at δ=165.9 and 309 ppm 13 C NMR resonances centered at δ=167.3 ppm

12 1 H NMR:δ 0.44 ppm (SiMe 3 ) 29 Si NMR:δ 24.41 ppm

13 The 1 H NMR spectrum of 2 exhibits two singlets at δ=0.24 ppm and 0.39 ppm and the 29 Si NMR spectrum reveals resonances at δ=6.16 and 24.41 ppm.

14 Conclutions Functionalization of a side-on bound hafnocene dinitrogen complex with carbon dioxide has been accomplished. Elaboration of the core of the molecule was accomplished by treatment with Me 3 SiI, resulting in the synthesis of a dicarboxylated silylated hydrazine directly from N 2 and CO 2.

15 Mechanism