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Isolation of the Metalated Ylides [Ph 3 P−C−CN]M (M=Li, Na, K): Influence of the Metal Ion on the Structure and Bonding Situation
Author(s) -
Schwarz Christopher,
Scharf Lennart T.,
Scherpf Thorsten,
Weismann Julia,
Gessner Viktoria H.
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201805421
Subject(s) - chemistry , delocalized electron , crystallography , potassium , lithium (medication) , metal , inorganic chemistry , sodium , antibonding molecular orbital , coordination number , ionic bonding , density functional theory , ion , atomic orbital , computational chemistry , electron , organic chemistry , medicine , physics , quantum mechanics , endocrinology
The isolation and structural characterization of the cyanido‐substituted metalated ylides [Ph 3 P−C−CN]M ( 1‐M ; M=Li, Na, K) are reported with lithium, sodium, and potassium as metal cations. In the solid‐state, most different aggregates could be determined depending on the metal and additional Lewis bases. The crown‐ether complexes of sodium ( 1‐Na ) and potassium ( 1‐K ) exhibited different structures, with sodium preferring coordination to the nitrogen end, whereas potassium binds in an unusual η 2 ‐coordination mode to the two central carbon atoms. The formation of the yldiide was accompanied by structural changes leading to shorter C−C and longer C−N bonds. This could be attributed to the delocalization of the free electron pairs at the carbon atom into the antibonding orbitals of the CN moiety, which was confirmed by IR spectroscopy and computational studies. Detailed density functional theory calculations show that the changes in the structure and the bonding situation were most pronounced in the lithium compounds due to the higher covalency.