PMID- 12401092
OWN - NLM
STAT- MEDLINE
DCOM- 20021209
LR  - 20190814
IS  - 0020-1669 (Print)
IS  - 0020-1669 (Linking)
VI  - 41
IP  - 22
DP  - 2002 Nov 4
TI  - Dichloroacetylene is not the precursor to dichlorinated vinylcobaloxime and 
      vinylcobalamin in cobalt catalyzed dechlorination of perchloro- and 
      trichloroethylene.
PG  - 5844-8
AB  - Vitamin B(12) catalyzes the reductive dechlorination of perchloroethylene (PCE), 
      a process for which vinylcobalamins have been proposed as intermediates. Previous 
      model studies have shown that PCE and trichloroethlylene (TCE) react with 
      cob(I)aloxime to form cis-1,2-dichlorovinylcobaloxime (1). This compound could be 
      formed by nucleophilic vinylic substitution of cob(I)aloxime on TCE or its 
      syn-addition to dichloroacetylene. To evaluate the latter possibility, 
      dichloroacetylene was reacted in this study with cob(I)aloxime. The major product 
      was not complex 1 but a novel cobalt complex, indicating that dichloroacetylene 
      is not involved in the reductive dechorination of PCE catalyzed by cob(I)aloxime. 
      An X-ray structure of the major product was obtained showing an unexpected 
      tricyclic structure in which one of the carbons of dichloroacetylene is a ligand 
      to the metal and the second carbon has formed a C-C bond to one of the oxime 
      carbons. This arrangement connects the axial and equatorial ligands. The cathodic 
      peak potential of this complex is significantly more negative than that of 
      previously characterized chlorinated vinylcobaloximes. Cob(I)alamin also reacts 
      with chloroacetylene to provide cis-chlorovinylcobalamin in analogy to 
      cob(I)aloxime, but it does not provide dichlorinated vinylcobalamins in the 
      reaction with dichloroacetylene. Hence, dichlorinated vinylcobalt complexes 
      detected in the reductive dechlorination of PCE catalyzed by cobaloximes or 
      vitamin B(12) are not derived from a dichloroacetylene intermediate.
FAU - McCauley, Kevin M
AU  - McCauley KM
AD  - Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South 
      Mathews Avenue, Urbana, IL 61801, USA.
FAU - Wilson, Scott R
AU  - Wilson SR
FAU - van der Donk, Wilfred A
AU  - van der Donk WA
LA  - eng
GR  - 1S10 RR 10444/RR/NCRR NIH HHS/United States
GR  - GM 27029/GM/NIGMS NIH HHS/United States
GR  - RR 01575/RR/NCRR NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Inorg Chem
JT  - Inorganic chemistry
JID - 0366543
RN  - 0 (Chlorides)
RN  - 0 (Organometallic Compounds)
RN  - 0 (Oximes)
RN  - 290YE8AR51 (Trichloroethylene)
RN  - 3G0H8C9362 (Cobalt)
RN  - 95I833JV4S (dichloroacetylene)
RN  - OC7TV75O83 (Acetylene)
RN  - P6YC3EG204 (Vitamin B 12)
RN  - TJ904HH8SN (Tetrachloroethylene)
SB  - IM
MH  - Acetylene/*analogs & derivatives/*chemistry
MH  - Catalysis
MH  - Chlorides/chemistry
MH  - Chromatography, Thin Layer
MH  - Cobalt/*chemistry
MH  - Crystallography, X-Ray
MH  - Electrochemistry
MH  - Magnetic Resonance Spectroscopy
MH  - Models, Molecular
MH  - Molecular Conformation
MH  - Organometallic Compounds/*chemistry
MH  - Oximes/*chemistry
MH  - Tetrachloroethylene/*chemistry
MH  - Trichloroethylene/*chemistry
MH  - Vitamin B 12/*chemistry
EDAT- 2002/10/29 04:00
MHDA- 2002/12/10 04:00
CRDT- 2002/10/29 04:00
PHST- 2002/10/29 04:00 [pubmed]
PHST- 2002/12/10 04:00 [medline]
PHST- 2002/10/29 04:00 [entrez]
AID - ic025714k [pii]
AID - 10.1021/ic025714k [doi]
PST - ppublish
SO  - Inorg Chem. 2002 Nov 4;41(22):5844-8. doi: 10.1021/ic025714k.