TY - JOUR
T1 - Synthetic, electrochemical, and theoretical studies of tetrairidium clusters bearing mono- and bis[60]fullerene ligands
AU - Park, Bo Keun
AU - Lee, Gaehang
AU - Kim, Kyoung Hoon
AU - Kang, Hongkyu
AU - Lee, Chang Yeon
AU - Miah, Md Arzu
AU - Jung, Jaehoon
AU - Han, Young Kyu
AU - Park, Joon T.
PY - 2006/8/30
Y1 - 2006/8/30
N2 - Heating a mixture of lr4(CO)9(PPh3) 3 (1) and 2 equiv of C60 in refluxing chlorobenzene (CB) affords a "butterfly" tetrairidium-C60 complex lr 4(CO)6{μ3-κ3-PPh 2(o-C6H4)P(o-C6H4) PPh(η1-o-C6H4}}-(μ3- η2:η2-C60) (3, 36%). Brief thermolysis of 1 in refluxing chlorobenzene (CB) gives a "butterfly" complex lr4(CO)8{μ-k2-PPh2(o-C 6H4)PPh}{μ3-PPh2(η 1:η2-o-C6H4)} (2, 64%) that is both ortho-phosphorylated and ortho-metalated. Interestingly, reaction of 2 with 2 equiv of C60 in refluxing CB produces 3 (41%) by C 60-assisted ortho-phosphorylation, indicating that 2 is the reaction intermediate for the final product 3. On the other hand, reaction of lr 4(CO)8(PMe3)4 (4) with excess (4 equiv) C 60 in refluxing 1,2-dichlorobenzene, followed by treatment with CNCH2Ph at 70 °C, affords a square-planar complex with two C 60 ligands and a face-capping methylidyne ligand, lr 4(CO)3(μ4-CH)(PMe3) 2(μ-PMe2)(CNCH2Ph)(μ-η2: η2-C60)(μ4-η1: η1:η2:η2-C60) (5, 13%) as the major product. Compounds 2, 3, and 5 have been characterized by spectroscopic and microanalytical methods, as well as by single-crystal X-ray diffraction studies. Cyclic voltammetry has been used to examine the electrochemical properties of 2, 3, 5, and a related known "butterfly" complex lr4(CO)6(μ-CO){μ3-k 2-PPh2(o-C6H4)P(η1-o- C6H4)}(η3-η2: η2:η2-C60) (6). These cyclic voltammetry data suggest that a C60-mediated electron transfer to the iridium cluster center takes place for the species 33- and 6 2- in compounds 3 and 6. The cyclic voltammogram of 5 exhibits six well-separated reversible, one-electron redox waves due to the strong electronic communication between two C60 cages through a tetrairidium metal cluster spacer. The electrochemical properties of 3, 5, and 6 have been rationalized by molecular orbital calculations using density functional theory and by charge distribution studies employing the Mulliken and Hirshfeld population analyses.
AB - Heating a mixture of lr4(CO)9(PPh3) 3 (1) and 2 equiv of C60 in refluxing chlorobenzene (CB) affords a "butterfly" tetrairidium-C60 complex lr 4(CO)6{μ3-κ3-PPh 2(o-C6H4)P(o-C6H4) PPh(η1-o-C6H4}}-(μ3- η2:η2-C60) (3, 36%). Brief thermolysis of 1 in refluxing chlorobenzene (CB) gives a "butterfly" complex lr4(CO)8{μ-k2-PPh2(o-C 6H4)PPh}{μ3-PPh2(η 1:η2-o-C6H4)} (2, 64%) that is both ortho-phosphorylated and ortho-metalated. Interestingly, reaction of 2 with 2 equiv of C60 in refluxing CB produces 3 (41%) by C 60-assisted ortho-phosphorylation, indicating that 2 is the reaction intermediate for the final product 3. On the other hand, reaction of lr 4(CO)8(PMe3)4 (4) with excess (4 equiv) C 60 in refluxing 1,2-dichlorobenzene, followed by treatment with CNCH2Ph at 70 °C, affords a square-planar complex with two C 60 ligands and a face-capping methylidyne ligand, lr 4(CO)3(μ4-CH)(PMe3) 2(μ-PMe2)(CNCH2Ph)(μ-η2: η2-C60)(μ4-η1: η1:η2:η2-C60) (5, 13%) as the major product. Compounds 2, 3, and 5 have been characterized by spectroscopic and microanalytical methods, as well as by single-crystal X-ray diffraction studies. Cyclic voltammetry has been used to examine the electrochemical properties of 2, 3, 5, and a related known "butterfly" complex lr4(CO)6(μ-CO){μ3-k 2-PPh2(o-C6H4)P(η1-o- C6H4)}(η3-η2: η2:η2-C60) (6). These cyclic voltammetry data suggest that a C60-mediated electron transfer to the iridium cluster center takes place for the species 33- and 6 2- in compounds 3 and 6. The cyclic voltammogram of 5 exhibits six well-separated reversible, one-electron redox waves due to the strong electronic communication between two C60 cages through a tetrairidium metal cluster spacer. The electrochemical properties of 3, 5, and 6 have been rationalized by molecular orbital calculations using density functional theory and by charge distribution studies employing the Mulliken and Hirshfeld population analyses.
UR - http://www.scopus.com/inward/record.url?scp=33748079491&partnerID=8YFLogxK
U2 - 10.1021/ja0616027
DO - 10.1021/ja0616027
M3 - Article
C2 - 16925434
AN - SCOPUS:33748079491
SN - 0002-7863
VL - 128
SP - 11160
EP - 11172
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 34
ER -