TY - JOUR
T1 - Bis-ortho-chelated arylcopper compounds. Synthesis and X-ray crystal structure of Cu4Br2[C6H3(CH2NMe 2)2-o,o′2
AU - Wehman, Erik
AU - Van Koten, Gerard
AU - Erkamp, Cornelis J M
AU - Knotter, D. Martin
AU - Jastrzebski, Johann T B H
AU - Stam, Casper H.
PY - 1989
Y1 - 1989
N2 - A novel arylcopper(I) compound has been prepared from the reaction of lithiated C6H4(CH2NMe2)2-o,o′ with CuBr. An X-ray crystal structure determination on this new compound revealed it not to be [Cu{C6H3(CH2NMe2) 2-o,o′}] but its 1:1 CuBr adduct (Cu4Br2C24H38N4; orthorhombic; Pcab; a = 18.167 (3), b = 19.462 (3), c = 17.036 (2) Å; Z = 8). The determined molecular structure shows a highly asymmetric [Cu4{C6H3(CH2NMe2) 2-o,o′}2Br2] molecule containing four differently coordinated copper atoms. The copper atoms, which are all three-coordinate, are in a butterfly arrangement which is kept together by two bridging C ipso atoms of the aryl ligands [Cu-C distance 2.074 (5) Å (mean)] and two bridging bromine atoms [Cu-Br distance 2.397 (1) Å (mean)]. The Cu-Cu distances for the two adjacent C-bridged bonds are 2.412 (2) and 2.406 (2) Å and for the Br-bridged bonds are 2.429 (2) and 2.737 (2) Å. The coordination pattern of the CH2NMe2 side arms is such that each of the copper atoms is N-coordinated [Cu-N distance 2.176 (4) Å (mean)], thus making them all three-coordinate. Variable-temperature 1H NMR measurements in the temperature range 233-373 K show that this asymmetric structure is not retained in solution and that a more symmetric molecule is formed. These spectra also show the existence of complex fluxional processes. Reaction of [Li2{C6H3(CH2NMe2) 2-o,o′}2] with CuBr{P(OMe)3} afforded an arylcopper compound whose formulation based on elemental analysis and 1H NMR data is [Cu2{C6H3(CH2NMe2) 2-o,o′}Br{P(OMe)3}2].
AB - A novel arylcopper(I) compound has been prepared from the reaction of lithiated C6H4(CH2NMe2)2-o,o′ with CuBr. An X-ray crystal structure determination on this new compound revealed it not to be [Cu{C6H3(CH2NMe2) 2-o,o′}] but its 1:1 CuBr adduct (Cu4Br2C24H38N4; orthorhombic; Pcab; a = 18.167 (3), b = 19.462 (3), c = 17.036 (2) Å; Z = 8). The determined molecular structure shows a highly asymmetric [Cu4{C6H3(CH2NMe2) 2-o,o′}2Br2] molecule containing four differently coordinated copper atoms. The copper atoms, which are all three-coordinate, are in a butterfly arrangement which is kept together by two bridging C ipso atoms of the aryl ligands [Cu-C distance 2.074 (5) Å (mean)] and two bridging bromine atoms [Cu-Br distance 2.397 (1) Å (mean)]. The Cu-Cu distances for the two adjacent C-bridged bonds are 2.412 (2) and 2.406 (2) Å and for the Br-bridged bonds are 2.429 (2) and 2.737 (2) Å. The coordination pattern of the CH2NMe2 side arms is such that each of the copper atoms is N-coordinated [Cu-N distance 2.176 (4) Å (mean)], thus making them all three-coordinate. Variable-temperature 1H NMR measurements in the temperature range 233-373 K show that this asymmetric structure is not retained in solution and that a more symmetric molecule is formed. These spectra also show the existence of complex fluxional processes. Reaction of [Li2{C6H3(CH2NMe2) 2-o,o′}2] with CuBr{P(OMe)3} afforded an arylcopper compound whose formulation based on elemental analysis and 1H NMR data is [Cu2{C6H3(CH2NMe2) 2-o,o′}Br{P(OMe)3}2].
UR - http://www.scopus.com/inward/record.url?scp=0003030856&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0003030856
SN - 0276-7333
VL - 8
SP - 94
EP - 99
JO - Organometallics
JF - Organometallics
IS - 1
ER -