N-Fluoropyridinium trifluoromethanesulfonate and 1-fluoro-2,4,6-trimethoxy-1,3,5-triazinium hexafluoroantimonate: the first experimental determination of the F—N⁺bond length involvingsp²nitrogen

Abstract

The structures of N-fluoropyridinium trifluoromethanesulfonate, C(5)H(5)FN(+).CF(3)O(3)S(-), (I), and 1-fluoro-2,4,6-trimethoxy-1,3,5-triazinium hexafluoroantimonate, (C(6)H(9)FN(3)O(3))[SbF(6)], (II), are presented. The N-F bond lengths in (I), a well known electrophilic fluorinating agent, and its novel analogue, (II), are 1.357 (4) and 1.354 (4) A, respectively.

Carbonyl Hypoiodites as Extremely Strong Halogen Bond Donors

“…Estimation of the N ‐iodopyridinium character is difficult as no N ‐iodopyridinium cation X‐ray structure is known (only the N ‐fluoropyridinium cation is known). [56] In the 3c‐4e [N−I−N] + halogen‐bonded symmetric halonium complex [ 2 −I− 2 ]PF 6 , the relative N ‐iodopyridinium character can be considered to be 50 % (N−I: 2.250 Å, N−N: 4.500 Å),[ 36 , 40 , 57 ] while for the [ 2 −I] + cation the I−N bond distance can only be obtained with computational methods (SI, section 3). The DFT computed value for the I−N bond distance in [ 2 −I] + is 2.042 Å.…”

1-Fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate: synthesis, characterization, and ability to effect electrophilic aromatic substitution

“…In view of the disorder problem encountered during an X-ray diffraction study of the hexafluoroarsenate 2 [1,2], no attempt has been made to undertake similar work with [(ClCN) 3 F] þ [BF 4 ] À (1) (complete reliable experimental X-ray data are available for only one N-fluoro-sym-triazinium salt, namely 1-fluoro-2,4,6-trimethoxy-1,3,5-triazinium hexafluoroantimonate [7]). The identity of this new salt rests, therefore, on its mode of synthesis, a good elemental analysis (C, B, N), NMR data, and its ability to act as a fluorine-plus (F þ ) source.…”

Carbonyl Hypoiodites as Extremely Strong Halogen Bond Donors

“…As expected, substituted pyridines such as DMAP ( 2 ) and 4‐piperidinopyridine ( 4 ), that are stronger nucleophiles, are better able to induce this increased N ‐iodopyridinium character in the O−I−N complexes described herein. Estimation of the N ‐iodopyridinium character is difficult as no N ‐iodopyridinium cation X‐ray structure is known (only the N ‐fluoropyridinium cation is known) [56] . In the 3c‐4e [N−I−N] + halogen‐bonded symmetric halonium complex [ 2 −I− 2 ]PF 6 , the relative N ‐iodopyridinium character can be considered to be 50 % (N−I: 2.250 Å, N−N: 4.500 Å), [36, 40, 57] while for the [ 2 −I] + cation the I−N bond distance can only be obtained with computational methods (SI, section 3).…”