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Journey from Mo-Mo quadruple bonds to quintuple bonds
Yi-Chou Tsai1, Hong-Zhang Chen, Chie-Chieh Chang
1Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC. yictsai@mx.nthu.edu.tw
Journal of the American Chemical Society
|August 19, 2009
Summary
Researchers synthesized novel dimolybdenum complexes with quadruple and quintuple bonds. These complexes exhibit the shortest metal-metal bonds yet observed beyond the first row of elements, confirmed by DFT calculations.
Area of Science:
- Inorganic Chemistry
- Materials Science
- Computational Chemistry
Background:
- Dimolybdenum complexes are known for exhibiting multiple metal-metal bonds.
- Paddlewheel structures are common in dimolybdenum chemistry.
- Exploring higher-order metal-metal bonds is crucial for understanding chemical bonding.
Purpose of the Study:
- To synthesize and characterize new dimolybdenum complexes with quadruple and quintuple bonds.
- To investigate the structural and electronic properties of these novel complexes.
- To explore the formation of the shortest metal-metal bonds beyond the first row elements.
Main Methods:
- Synthesis of dimolybdenum complexes via reaction of K(4)Mo(2)Cl(8) with Li[RC(NDipp)(2)] ligands.
- Structural characterization using X-ray crystallography.
- Electronic structure analysis using Density Functional Theory (DFT) calculations.
Main Results:
- Two paddlewheel-type quadruply bonded dimolybdenum complexes, Mo(2)(mu-Cl)[Cl(2)Li(OEt(2))][mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2), were synthesized.
- Reduction of these complexes yielded Mo-Mo quintuple bonded complexes, Mo(2)[mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2), with significantly shorter Mo-Mo bond lengths.
- The resulting Mo-Mo bond lengths represent the shortest metal-metal bonds observed beyond the first row elements.
Conclusions:
- The successful synthesis of dimolybdenum complexes with quadruple and quintuple bonds expands the scope of multiple bonding in inorganic chemistry.
- The observed shortest metal-metal bonds provide insights into the nature of bonding in heavy transition metals.
- DFT calculations corroborate the presence of quintuple bonding and the structural characteristics of the synthesized complexes.
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