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14 Cards in this Set
- Front
- Back
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How to calculate PSEP of BH cluster |
Each BH vertex contributes 2 electrons (2 PSE) every remaining hydrogen contributes 1 electron and add one for each negative charge and subtract one for positive. Divide total number of PSE by 2 to give PSEP: number of electron pairs |
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What can be deduced if there are m PSEPs? |
The parent geometry is based on a closo-deltahedron with (m-1) vertices |
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If there are n BH vertices and (n+1) PSEP,what can be deduced? |
The structure is that of the parent closo-deltahedron |
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If there are n BH vertices and (n+2) PSEP,what can be deduced?
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The structure is that of the nido-deltahedron. Vertex of highest connectivity missing |
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If there are n BH vertices and (n+3) PSEP,what can be deduced? |
The structure is that of the arachno-deltahedron. 2 Vertexes of highest connectivities missing |
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What happens to extra hydrogens in Nido and Arachno clusters? |
They do not fill cage sites but are terminal or bridging and point towards missing vertex. |
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When are Wade's rules not applicable? |
When there are less than 5 PSEP's in the parent deltahedron |
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How many electrons does a CH unit contribute?
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3 PSE |
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How many electrons do group 14 metals contribute? |
2 PSE |
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How many electrons does a Bi unit contribute? |
3 PSE |
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Under what circumstances do Wade's rules not apply? |
When there are less than 5 PSEP's in the parent deltahedron. Bi9 (5+) as closo strucutre requires 10 PSEP not 11, has electron pair in a low lying non-bonding orbital Some stable halide clusters Assumes only bonding orbitals filled |
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Draw closo structure |
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Draw nido structure |
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Draw arachno structure |
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