3,5-Bis[(dimethylamino)methyl]-1-nitro-4-(trimethylsilyl)benzene

Abstract

The title compound, C 15 H 27 N 3 O 2 Si, which is an NCN {NCN = 2,6-bis[(dimethylamino)methyl]phenyl} pincer ligand, nitrosubstituted in the para position, features intramolecular C-HÁ Á ÁN and intermolecular C-HÁ Á ÁO hydrogen-bond contacts producing dimeric units. The Si atoms are essentially tetrahedral with normal bond lengths and angles. The nitro groups are in the planes of the corresponding benzene rings and the amino groups are mutually trans. Despite the presence of four independent molecules in the asymmetric unit, all of which have essentially the same geometry, there is no pseudotranslational symmetry present.

Playing around with MP, a tool for the analysis of pseudosymmetry: recurrent appearance of local pseudo-space groups in the asymmetric unit of Z′ = 4 structures

“…(c) And finally, what we consider to be the most stringent validation of the PS description, the way in which all four molecules in the AU collapse under the application of the mimicked SG operations (performed using the UNIQ instruction in XP). Case 4c is for CSD refcode CICQAH (von Chrzanowski et al, 2007) and Case 4d for DUTGAB (Khan et al, 2010). The colour code is as in Fig.…”

“…The colour code is as in Fig. 3. 3 The complete set includes cases 4a with CSD refcode BERSUM (Gzella et al, 1999); 4b BIJDON05 (Ng, 2011); 4c CICQAH (von Chrzanowski et al, 2007); 4d DUTGAB (Khan et al, 2010); 4e GUFKAT (Blake et al, 1999); 4f LEFRIZ (Khalaji et al, 2012); 4g MUCJIE (Lu et al, 2009); 4h NOZVIH (Dobson & Gerkin, 1998); 4i QIMMAA (Bats et al, 2001); 4j RAHDUC (Piccialli et al, 2017); 4k GOFQUO (Fairuz et al, 2008); 4l WERNOW (Tinant et al, 1994); 4m RIZCEJ (Gró f et al, 2008); 4n BOKXII (Hickel et al, 1983); 4o PELLIC (Cuffini et al, 2006); 4p TIJPUX (Kato et al, 2001); 4q UKIZUK (Budesinsky et al, 2010); 4r UPAXUF (Xie & Zhao, 2011); 4s XODYAS (Burrett et al, 2014); 4t CICROW (Kettmann et al, 2007); 4u ABADIS02 (Kuai & Cheng, 2011); 4v PAVRUB (Owczarzak & Kubicki, 2012); 4w TEJPAZ (Alcock et al, 1996); 4x GALBEB (Britton, 2005).…”

“…298 K for BIJDON04 and 100 K for BIJDON05), a phase transition linking the monoclinic form BIJDON04 and the triclinic pseudo-monoclinic form BIJDON05 is highly probable. Chrzanowski et al, 2007). Results are summarized in Fig.…”