Magnesium Cyanide or Isocyanide?

Abstract

Preference for the binding mode of the CN À ligand to Mg (Mg À CN vs.Mg À NC) is investigated. Amonomeric Mg complex with at erminal CN ligand was prepared using the dipyrromethene ligand Mes DPM which successfully blocks dimerization. While reaction of ( Mes DPM)MgN(SiMe 3 ) 2 with Me 3 SiCN gave the coordination complex ( Mes DPM)MgN-(SiMe 3 ) 2 ·NCSiMe 3 ,r eaction with ( Mes DPM)Mg(nBu) led to ( Mes DPM)MgNC·(THF) 2 .AM g À NC/Mg À CN ratio of % 95:5 was established by crystal-structure determination and DFT calculations.IRstudies show absorbances for CN stretching at 2085 cm À1 (MgÀNC) and 2162 cm À1 (MgÀCN) as confirmed by 13 Clabeling.Insolution and in the solid state,the CN ligand rotates within the pocket. The calculated isomerization barrier is only 12.0 kcal mol À1 and the 13 CNMR signal for CN decoalesces at À85 8 8C( Mg À NC:1 75.9 ppm, Mg À CN: 144.3 ppm). Experiment and theory both indicate that Mg complexes with the CN À ligand should not be named cyanides but are more properly defined as isocyanides.

Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull

“…However, additional bands of the C�N triple bond are observed at 2079 cm À 1 (CN@1) or at 2036 cm À 1 ( 13 CN@1), respectively. [53] These results are consistent with the calculated stretching frequencies of the C�N triple bond including the respective isotope, and are in agreement with the corresponding value of solid sodium cyanide with 2091 cm À 1 . [54] Other trimethylsilyl compounds of inorganic ions were tested in similar reactions.…”

Assembly of metallo-macrocycles through reductive C–C coupling of alkylnitriles by an Mg–Mg-bonded compound

“…In the amido-ene-nitrile moieties, the C-C bond lengths fall in the range 1.387(12)-1.459(13) Å, which are intermediate between C-C and CvC bonds. 47 The lengths of CuN triple bonds (1.187(10), 1.173( 9) and 1.193(13) Å) are comparable to those of coordinated CuN (1.14 Å) bonds, 9 and the bond lengths of C-N (1.351 (11), 1.346 (10), and 1.326(12) Å) are slightly shorter than the common C sp 2-N single bond. 47 In the amido-ene-nitrile bridges, the angles at the newly coupled carbon atoms (e.g.…”

“…[1][2][3] The activation mode of aromatic nitriles normally undergoes C-C or C-N coupling processes of two or more substrate molecules. [4][5][6][7] In comparison, for aliphatic nitriles, there are relatively diverse reaction pathways, including release of the cyanide ion (CN − ) to bridge metal ions, [8][9][10][11][12] C-C or C-N couplings of CN groups, [12][13][14][15] deprotonation of the α-H atom (e.g. for isobutyronitrile, cyclohexyl nitrile, etc.)…”

“…[19][20][21] These reactions can be mediated by a variety of metal complexes (mostly mononuclear ones). [4][5][6][7][8][9][10][11][14][15][16][17][18][19][20][21] In recent years, the low-valent metal-metal-bonded compounds have been increasingly employed in small molecule activation. [22][23][24][25] Especially, for the Mg-Mg bond, several reaction types are known toward nitriles (and isonitriles).…”

Dipyrrin based metal complexes: reactivity and catalysis

“…Interestingly, the specific sterics of this particular ligand was recently taken advantage of to isolate and identify a magnesium isocyanide compound and a germylene monochloride species. [119][120] Fig. 18 Mg(II) complex 60 as initiator of ring opening polymerization of lactide (top) and -caprolactone (bottom) as described by Chisholm et al 118 The group of Mason has investigated the ring-opening polymerization activity of Al(III) analogues of 60, with a phenyl at the meso position and either alkoxide or amide ligands.…”