Received 17 January 2013
In the crystal structure of the title salt, C12H30N42+·2C24H20B-, the C-N bond lengths in the central CN3 unit of the guanidinium ion are 1.3388 (17), 1.3390 (16) and 1.3540 (17) Å, indicating partial double-bond character in each. The central C atom is bonded to the three N atoms in a nearly ideal trigonal-planar geometry and the positive charge is delocalized in the CN3 plane. The bonds between the N atoms and the terminal C-methyl groups of the guanidinium moiety, all have values close to a typical single bond [1.4630 (16)-1.4697 (17) Å]. C-H interactions are present between the guanidinium H atoms and the phenyl C atoms of one tetraphenylborate ion. The phenyl rings form a kind of aromatic pocket, in which the guanidinium ion is embedded.
For the synthesis of N''-[3-(dimethylamino)propyl]- N,N,N',N'-tetramethylguanidine, see: Tiritiris & Kantlehner (2012). For the crystal structures of alkali metal tetraphenylborates, see: Behrens et al. (2012).
Data collection: COLLECT (Hooft, 2004); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZL2530 ).
The author thanks Dr F. Lissner (Institut für Anorganische Chemie, Universität Stuttgart) for measuring the crystal data.
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