Synthesis, structure and spectroscopic properties of bis(triphenylphosphane)iminium (phenylacetylido)(cyanido)aurate(I) monoacetone monohydrate, (PPN)[Au(CN)(CCC6H5)]·H2O·(CH3)2CO and bis(triphenylphosphane)iminium (t-butylacetylido)(cyanido)aurate(I) monohydrate, (PPN)[Au(CN)(CCC4H9)]·H2O

The N-atom in [N(PR3)2]+ cations (R = Ph, Me) can act as electron donor for (pseudo) anti-electrostatic interactions

“…1a and b are perspective views of a very recent [PPN] + containing crystal structure, ijPPN] + [Au(CN) (CCPh)] − . 7 As is indicated in the figures, short intramolecular C-H⋯N contact distances (2.55-2.63 Å) are present that lie within the sum of the van der Waals radii of H (1.09 Å) and N (1.55 Å). 16 Such short contacts are indicative of hydrogen bonding and seem to have been largely overlooked in the past.…”

“…To obtain more insight into the physical origins of these intramolecular features, the geometry of 1 as found 7 in ijPPN] + [Au(CN)(CCPh)] − was subjected to DFT computations on the BP86-D3/def2-TZVP level of theory (see ESI † for details). Shown in Fig.…”

“…We wondered if perhaps the N-atom is also capable of engaging in intermolecular interactions, to which end we conducted some additional DFT studies and performed a detailed survey of the CSD. We choose ijNIJPMe 3 ) 2 ] + as a simplified model compound and calculated its complexation energies with several neutral (2-6) and cationic (7)(8)(9)(10)(11) species at the BP86-D3/def2-TZVP level of theory (see ESI † for details). The results are summarized in Table 1.…”