1. Group Meeting
Literature Review: Main Group,
Four Membered Heterocycles
July 18, 2012
Stewart Lucas

2. Cyclic Distiba- and
Dibismadiazenium Cations1
Mathias Lehmann, Axel Schulz, and Alexander Villinger
Angew. Chem. Int. Ed., 2012, Advance Article
Universität Rostock, Institut für Chemie, Albert-Einstein-Strasse 3a,
and Leibniz-Institut für Katalyse e.V. an der Universität Rostock Albert-
Einstein-Strasse 29a, 18059 Rostock (Germany)

3. Four-membered Pnictogen-Nitrogen
Heterocycles
• 1,3-dihalogen-cyclo-1,3-dipicta(III)-2,4-diazenes.
• E = P: Used in preparative phosphorus-nitrogen chemistry
(macrocycles, polymers, main-group complexes, and
generation of cyclic binary PN cations)2-6.
• Diazanes with bulky R groups provide kinetic
stabilization7-13.
• Lewis acids used to generate cyclo-1,3-dipnicta(III)-2,4-
diazenium cations14-16.
• Ion pairs with large interatomic distances.

4. Four-membered Pnictogen-Nitrogen
Heterocycles
• 1,3-dihalogen-cyclo-1,3-dipicta(III)-2,4-diazenium
cations.
• Antimony and bismuth analogs are unknown.
• Few examples of
17-21
N-E+-N compounds are known.
• The [Me2Si(µ-NR)2E]+ contains strong intermolecular
Draw out [ClE(µ-NTer)]2,
interactions.
[XE(µ-NTer)2E]+and [E2(µ-
• This paper presents the synthesis of NR)2]2+.
[ClE(µ-NTer)]2 which is subsequently used to
generate [XE(µ-NTer)2E] + and [E (µ-NR) ]2+
2 2 .

5. Synthesis of Dipictadiazanes and
Dipnictadiazenium Cations
• [ClE(µ-NTer)]2 from HCl elimination of RNH2 and
ECl3 or RHN-ECl2. Draw out HCl emim
• When E = Sb or Bi side reactions occur which lead to
scheme
reduced yield of [ClE(µ-NTer)]2. Yield?
• Alternate route to [ClE(µ-NTer)]2 involves a
distannadiazane.
• Formed via metallation of a primary amine and a Sn(II)
diamide.
• [ClSn(µ-NTer)]2 has been reported by Power.

6. Synthesis of Dipictadiazanes and
Dipnictadiazenium Cations
• Reaction of pnictogen(III) chlorides with the
distannadiazane yields dipnictadiazanes.
• Yield for Sb species: 79%, Bi species: 68%.
Reaction scheme
• Addition of GaCl3 to [ClSb(µ-NTer)]2 results in the
formation of [ClSb(µ-NTer)2Sb][GaCl4].
Reaction scheme

7. Synthesis of Dipictadiazanes and
Dipnictadiazenium Cations
• Addition of GaCl3 to [ClBi(µ-NTer)]2 yields a dark-
brown solution (1H, 13C NMR suggest formation
of [ClBi(µ-NTer)2Bi]+).
Reaction scheme
• Attempts to isolate [ClBi(µ-NTer)2Bi][GaCl4] result
in decomposition.
• SbCl5 and Ag[SbF6] yielded same results.
• A more weekly coordinating anion was expected to help.
Ag[B(C6F5)4] still resulted in decomposition.

8. Synthesis of Dipictadiazanes and
Dipnictadiazenium Cations
• The iodine species, [IBi(µ-NTer)]2, was expected
to be more easily isolated.
• [ClE(µ-NTer)]2 converted to [E(µ-NTer)]2[OTf]2 (Sb: 65%,
Bi: 88%) by reaction with AgOTf
• [Bi(µ-NTer)]2[OTf]2 is then transformed to [IBi(µ-NTer)]2
(68%) by reaction with Me3SiI.
Reaction scheme
• Reaction of [IBi(µ-NTer)]2 with Ag[B(C6F5)4] led to
[IBi(µ-NTer)2Bi][B(C6F5)4]●3CH2Cl2 (46%).
Reaction scheme

9. Synthesis of Dipictadiazanes and
Dipnictadiazenium Cations
• fffssadsre

10. • f-number

11. Tellurium–Nitrogen -
Heterocyclic Chemistry
Mathias Lehmann, Axel Schulz, and Alexander Villinger
Angew. Chem. Int. Ed., 2012, Advance Article
Universität Rostock, Institut für Chemie, Albert-Einstein-Strasse 3a,
and Leibniz-Institut für Katalyse e.V. an der Universität Rostock Albert-
Einstein-Strasse 29a, 18059 Rostock (Germany)

12. References
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5. Beswick, Wright, Coord. Chem. Rev. 1998, 176, 373.
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14. Michalik, Schulz, et. al., Angew. Chem. Int. Ed. 2008, 47, 6465.
15. Schulz, Villinger, Inorg. Chem. 2009, 48, 7359.
16. Cowley, Kemp, Chem. Rev. 1985, 85, 367.
17. Veith, Bertsch, Z. Anorg. Allg. Chem. 1988, 557, 7.
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19. Veith, Angew. Chem. Int. Ed. Engl. 1987, 26, 1.
20. Gudat, Gans-Eichler, et. al., Chem. Commun. 2004, 2434.
21. Spinney, Korobkov, et. al., Chem. Commun. 2007, 1647.