Premium
Synthesis and Properties of Donor/Acceptor‐Substituted Metal‐Capped Twofold‐Sila‐Bridged Cyclobutadieno Superphanes
Author(s) -
Schaller Rolf Jens,
Haberhauer Gebhard,
Gleiter Rolf,
Rominger Frank
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200209)2002:9<2296::aid-ejic2296>3.0.co;2-7
Subject(s) - chemistry , cyclobutadiene , cobalt , acceptor , cyclic voltammetry , metal , delocalized electron , medicinal chemistry , stereochemistry , crystallography , electrochemistry , inorganic chemistry , organic chemistry , molecule , electrode , physics , condensed matter physics
The synthesis of the tetrasilasuperphanes 10 − 18 can be achieved from 1,1,3,3‐tetramethyl‐1,3‐disilacyclonona‐4,8‐diyne ( 7 ), 1,1,2,2‐tetramethyl‐1,2‐disilacyclonona‐3,8‐diyne ( 8 ) or 1,1,4,4‐tetramethyl‐1,4‐disilacyclodeca‐5,9‐diyne ( 9 ) by heating with [RCpCoL 2 ] [R = H, Si(CH 3 ) 3 , (CH 3 ) 5 , CO 2 CH 3 ; L 2 = COD, (CO) 2 , (C 2 H 4 ) 2 ]. The reaction of 7 with [RCpCo(CO) 2 ] [R = H, CH 3 , Si(CH 3 ) 3 , (CH 3 ) 5 ] produces the tricyclic cobalt‐stabilized cyclobutadienediynes 20 − 23 , whereas reaction with [R′CpCo(L 2 )] [R′ = H, (CH 3 ) 5 , CO 2 CH 3 ; L 2 = COD, (CO) 2 ] leads to the donor/acceptor superphanes 24 − 31 . X‐ray investigations on the superphanes 10 , 13 − 15 and 18 reveal distances between the two cyclobutadiene units in the range of 2.65 Å and 3.79 Å. Investigations by means of cyclic voltammetry of the superphanes 10 − 18 show a dependence of the oxidation potentials on the nature of the bridges. A comparison between the first oxidation potentials of 10 / 28 , 24 / 29 , and 26 / 31 gives evidence for a partial charge delocalization over both CpCoCbd fragments of the superphanes. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)