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Research draft

molecular geometry

vr.tr.molecular-geometry · XCT.QLT

Let an agent explain molecular geometry and its common shapes, relay VSEPR and related theories and experimental methods from chemistry references, describe coordination geometry, and distinguish molecular geometry from electron geometry, molecular structure in the connectivity sense and crystal structure.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain molecular geometry and its common shapes, relay VSEPR and related theories and experimental methods from chemistry references, describe coordination geometry, and distinguish molecular geometry from electron geometry, molecular structure in the connectivity sense and crystal structure.

The three-dimensional arrangement of atoms in a molecule, including bond lengths, bond angles and torsion angles, which determines properties such as polarity, reactivity and biological activity, described by shapes such as linear, trigonal planar, bent, tetrahedral, trigonal pyramidal, seesaw, square planar and octahedral, predicted by VSEPR theory and hybridisation and, for metal complexes, described as coordination geometry; molecular geometry is determined experimentally by diffraction and spectroscopy.

What it is for: Not applicable; a chemical concept.

It can be explain shapes and theory; relay methods; describe coordination geometry; distinguish related concepts.

Distinguishing features

Bond angles and lengths

Predicted by VSEPR

Determines properties

Measured by diffraction

What it looks like

Not a visible object; shapes shown in models.

Physical character

tetrahedral angle: 109.5 degrees

water bond angle: about 104.5 degrees

common coordination numbers: 2 to 6 and higher range

How it is recognised

Three-dimensional arrangement of atoms

Linear, trigonal planar, trigonal pyramidal, tetrahedral, seesaw, square planar, octahedral; coordination geometry

Electron geometry counts lone pairs; connectivity is the bonding pattern; crystal structure is the lattice

Related models

is a kind of - in registry terms

shape

is predicted by - from electron pairs

VSEPR theory

is measured by - and spectroscopy

X-ray crystallography

includes - for metal complexes

coordination geometry

In practice

Families and kinds

linear geometry

trigonal planar and bent geometries

tetrahedral and trigonal pyramidal geometries

trigonal bipyramidal, seesaw and T-shaped geometries

octahedral, square pyramidal and square planar geometries

coordination geometries of metal complexes

Standards and regulation

IUPAC definitions and nomenclature for geometry and stereochemistry

No regulation

Failure modes and hazards

Confusing molecular and electron geometry

Overreliance on VSEPR for transition metals

Confusing shape names

Also called

coordination geometrysquare planar molecular geometrytrigonal planar molecular geometrytrigonal pyramidal molecular geometrylinear molecular geometryseesaw molecular geometrysquare pyramidal molecular geometryoctahedral molecular geometryT-shaped molecular geometrytetrahedral molecular geometrypentagonal pyramidal molecular geometrytrigonal bipyramidal molecular geometrypentagonal planar molecular geometryCapped square antiprismatic molecular geometrycarbohydrate conformationmacromolecular structureCapped octahedral molecular geometryCapped trigonal prismatic molecular geometryDodecahedral molecular geometryBicapped trigonal prismatic molecular geometrypentagonal bipyramidal molecular geometrybent molecular geometrySquare antiprismatic molecular geometryTricapped trigonal prismatic molecular geometrytrigonal prismatic molecular geometryhistone codesolution structure

Where this came from

wikidata · CC0 1.0

Source repository Registry entry point

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Understand What molecular geometry is.

Science.

Definition

Definition.

Definition

Definition.

  1. What is molecular geometry, and how does it differ from electron geometry, connectivity and crystal structure? definition
  2. Is the question about molecular geometry, coordination geometry or crystal structure? boundary

Shapes

Shapes.

Shapes

Shapes.

  1. What are the linear, trigonal planar, bent, tetrahedral, trigonal pyramidal, seesaw, square planar and octahedral shapes? definition
  2. Which entry fits the specific shape? action
Predict Theory.

Science.

VSEPR

VSEPR and hybridisation.

VSEPR

VSEPR.

  1. How do VSEPR theory and hybridisation predict molecular shapes, and where do they fail? provenance
  2. Which references are standard? provenance

Computation

Computational methods.

Computation

Computation.

  1. How do quantum chemical calculations determine geometry? provenance
  2. Which sources are cited? provenance
Measure Measurement.

Practice.

Methods

Experimental methods.

Methods

Methods.

  1. How are geometries determined by X-ray, neutron and electron diffraction and by spectroscopy? provenance
  2. Which entry fits X-ray crystallography? action

Coordination

Coordination geometry.

Coordination

Coordination.

  1. How are coordination geometries of metal complexes described and predicted? provenance
  2. Which entry fits coordination complex? action
Context Importance and history.

Context.

Importance

Why it matters.

Importance

Importance.

  1. How does geometry affect polarity, reactivity, drug binding and materials? provenance
  2. Which entry fits stereochemistry? action

History

History.

History

History.

  1. How did van t Hoff, Le Bel, Werner and Gillespie develop the understanding of molecular shape? provenance
  2. Which entry fits the history of chemistry? action

What the second pass must settle

  • Should VSEPR theory and coordination geometry be separate primary entries?
  • How should chemistry references be linked?
  • The registry entry has merged aliases naming specific shapes; should they be split off?
Draft as JSON