electron pairs - 2024 ACF Winter at Brandeis

Question

In a rather alphabetically convenient scheme, the Jemmis rules require a cluster to have m + n + o + p − q pairs of these things. For 10 points each:

[10e] Name these things, “skeletal” pairs of which are counted by Wade’s rules. In a Lewis diagram, these things are indicated by dots placed around atomic symbols.

ANSWER: electron pairs [or lone pairs; or nonbonding electrons; accept skeletal electron pairs]

[10m] Polyhedral skeletal electron pair theory is used to predict the structure of clusters of this element, as in Wade’s rules. The canonical 3-center-2-electron bond is found in a compound containing this element and hydrogen.

ANSWER: boron [accept diborane or borane]

[10h] Wade’s rules give this prefix to a boron cluster that has n vertices and n + 1 skeletal electron pairs. This prefix, contrasted with nido- and arachno-, indicates that a cluster compound is a complete deltahedron.

ANSWER: closo-borane [or closo clusters]

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Summary


2024 ACF Winter at Clemson	2024-11-16	Y	1	20.00	100%	100%	0%
2024 ACF Winter at Lehigh	2024-11-16	Y	6	13.33	83%	33%	17%
2024 ACF Winter at Northwestern	2024-11-16	Y	9	18.89	100%	78%	11%
2024 ACF Winter at Ohio State	2024-11-16	Y	7	15.71	100%	57%	0%
2024 ACF Winter at Online	2024-11-16	Y	8	11.25	100%	13%	0%
2024 ACF Winter at UBC	2024-11-16	Y	3	16.67	100%	33%	33%
2024 ACF Winter at Central Florida	2024-11-16	Y	5	14.00	100%	20%	20%
2024 ACF Winter at Brandeis	2024-11-16	Y	9	16.67	100%	56%	11%

Data


Amherst A	Boston University B	10	10	0	20
Boston University A	Clark A	10	0	0	10
Yale B	Bowdoin B	10	10	0	20
Tufts A	Brown A	10	0	0	10
Yale C	Carabrandeis	10	0	0	10
Bowdoin A	Diamond Brandeis	10	0	0	10
Harvard A	Tufts B	10	10	10	30
MIT A	Brandeises Brew	10	10	0	20
Yale A	Northeastern A	10	10	0	20