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Dive into the world of atomic orbitals and molecular geometry by exploring hybridization theory. Learn how to predict molecular shapes based on sp3, sp2, and sp hybridization, and understand the implications for double and triple bonds. Gain insights into experimental data interpretation and molecular geometry calculations.
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Lecture 1 Section 1.2-3 - revision – atomic orbitals and shapes (1.2) - relate to dot cross diagrams (1.4) Problem 1.6 – class work Section 1.5, 1.6 and 1.7 - thermodynamics (not necessary) - sp3 hybridisation – explanation that hybridisation is a way of explaining experimentally determined molecular shape. Problems 1.8– class work Section 1.8 - sp2 hybridisation and p bonds Section 1.9 - sp hybridisation and double p bonds Problems 1.10, 1.13 – class work Introduction to ChemSketch: http://www.freechemsketch.com/
Lecture 1 Lone Pair electrons Sp3, sp2, sp hybridisation and prediction of molecular geometry s and p bonds
Homework Questions 1.28 (b) and (c) 1.31 (b) and (c) 1.32 1.44 1.49 Practice Questions 1.28 (a) 1.31 (a) 1.41 1.46 Homework to be handed in by next Monday 8 March 2010 Extra Reading – Section 1.10
Implications of preceding slides • Hybridisation is actually a mathematical tool to re-form the 4 orbitals • (s and p orbitals) 2. It is a useful theory to explain why Carbon 2s2, 2p2 – is able to form compounds with tetrahedral, trigonal and linear geometry • 3. Helps to explain the nature of a double C=C bond – actually a sigma • And a pi bond – one bond is weaker than the other – one bond • Is more ‘delocalised’ than the other – important for mechanism later Summary – for most organic compounds – C, N, O All single bonds – sp3 – based on tetrahedral geometry – 109.5 One double bond – sp2 – based on trigonal geometry - 120 One triple bond – sp –based on linear geometry - 180
1 carbon surrounded by 4 hydrogens Equidistant and 109o SUMMARY OF LECTURE 1 / CHAPTER 1 Experimental Data (eg spectroscopy, X-ray diffraction) Theoretical Explanation These techniques tell us where the atoms are – From there we calculate/measure bond angles and bond lengths Theories to explain why molecuels have certain shapes In real life…… Interpreted this data as…… We find e.g. C-H – carbon-hydrogen single bond sp3 hybridisation explains geometry Draw diagram
Interpreted this data as…… In real life…… we find e.g… 1 carbon surrounded by 2 hydrogens and 1 carbon, 120o Distance - ?? C-H – carbon-hydrogen single bond Carbon is Sp2 hybridised
But…. in school up to now….. I See Line-diagram in text book Interpret Single/double triple bonds Predict bond Angles and lengths Assign hybridisation