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Everything posted by Tartaglia

  1. Unfortunately Vedmecum, it is indeed due to the reversible 1e (bent ) NO and 3e (linear) NO interconversion. There are a number of other ligands which show similar effects eg the indenyl ligand which can flip eta-3 to eta-5. The complexes above are coordinatively unsaturated, the 1e (bent) NO configuration makes them electronically unsaturated 16e species, which then exhibit very low activation energy associative ligand substitution mechanisms
  2. cis is point group C2v and trans is C2h For cis the symmetric stretch A1 is active in the z direction (C2 axis) not in the x or y so as the C=C is in direction x or y it can't be active For trans the symmetric stretch Ag is not active in x,y or z. and the C=C is in the x or y direction Or more obviously, there is no change in dipole in either on a C=C stretch
  3. Associative as NO can reversibly act as a 1e or a 3e donor
  4. Its actually even simpler than that. Since 99% of C-13 nmr are proton decoupled, the vinyl protons in 3-methylhexene will both exhibit Nuclear Overhauser enhancement, but only one will in the 1-methylcyclohexene Merged post follows: Consecutive posts mergedThat should ofcourse have been "vinyl carbons" not "vinyl protons"
  5. H2SO4 is basically a catalyst, it is returned at the end
  6. Bascule, With regard to the effect of doubling the minimum banking reserve requirements, you should consider the following: the maximum money multiplier is the reciprocal of the minimum reserve requirements. Thus for a given monetary base M0, doubling the reserve requirement could in theory half the broad money measure (M2 or M4 depending on country or era). In 1936/7 there was however a lot of slack in the system and so it didn't have such a dramatic effect, it was however a substantial monetary tightening. Any reduction at all in the broad money supply will usually precipitate a recession As regards references, I pulled the following books of my shelf which all alluded to this extraordinary tightening J K Galbraith "Money Whence it came, where it went" p226-7 "The Great depression" M A Bernstein, p12 gives a number of scholarly references in footnote 12 C P Kindleberger "The World in Depression" p272 I could easily find more. J K Galbraith refers to this breathtaking incompetence many times in his other books
  7. I think you still misunderstand the difference between monetary policy and fiscal policy. Changing reserve requirements is definitely monetary policy, ie it affects money supply and market interest rates. It isn't anything to do with government expenditure or taxation (fiscal policy). One does have indirect effects on the other though. Changes in reserve reuirements were 16/8/36 13% to 19.5% 1/3/37 19.5% to 22.75% 1/5/37 22.75% to 26 % (Quoted for central reserve banks) Thus a doubling of reserve requirements was made over a period of 9 months. No wonder the money supply contracted again. This was probably the worst of a number of blunders made by the Federal Reserve during this period.
  8. Because its monetary policy not fiscal policy. http://en.wikipedia.org/wiki/Monetary_Policy http://en.wikipedia.org/wiki/Fiscal_policy
  9. The 1937 recession was due more to the unnecessary increases in banking reserve requirements, than tightened fiscal policy
  10. My feeling is that the debt accumulation that had built up prior to 1929 had been liquidated by the time FDR came to power and so Keynesian pump priming probably did no short term harm. However the New Deal vastly increased the power of the state and from a libertarian point of view that was not a good thing in the long run. The way things differ now is that Keynesian pump priming is being used before the debt has been liquidated and therefore the necessary debt liquidation will be longer, more painful and possibly ultimately hyperinflationary. This is a state of affairs which is potentially far more serious than a deflationary depression
  11. The -ve charge is delocalised ortho and para to the halide carrying carbon and so the presence of eg NO2 groups ortho and para can delocalise the charge by a negative conjugative effect. The intermediates are known as Meisenheimer complexes
  12. You need to be clearer in your question. I think you mean the stereochemistry of the alcohol which you are reacting with SOCl2 not the stereochemistry of SOCl2 which is planer. Also DMSO is a polar solvent not a non polar solvent
  13. Zellinger, OK point taken about the difference beween a solid object existing in enantiomeric forms, being different from a "behaviour" without a plane of symmetry. The non-chiral molecule moving in a helical path is an interesting one. Consider this "thought" experiment. Assuming we could bombard an enzyme active site (chiral in nature) with non chiral charged substrate moving in right and left handed helices. I would expect the activation energy for enzyme/substrate complex formation to differ as the pathways into the activated site to be hindered to different extents. Thus the non chiral substrate takes on the sort of property that chiral substrates would exhibit in forming diastereomeric enzyme/substrate complexes ie differing activation energy. This obviously isn't a practical proposition but is this phenomenom really as clear cut as you think?
  14. Circularly polarised light has a rotating E vector with the same symmetry as an infinite screw thread. Since screw threads can be right and left handed, so can circularly polarised light
  15. I would expect hydrazine as the first product 2NH2- + I2 --> N2H4 + 2I-
  16. I think it stops at Manganese (IV) oxide MnO4- + 2H2O + 3e --> MnO2 + 4OH-
  17. If you imagine the metal metal bond in the z direction then s, pz, f5z3-3zr2 are of the correct symmetry for sigma bonds (0 nodes), px, py, dxz,dyz, f5xz2-xr2 and f5yz2-yr2 are of the correct symmetry for pi bonding (1 node) , dx2-y2, dxy, fxyz and fzx2-zy2 are of the correct symmetry for delta bonding (2 nodes) and fy3-3yx2 and fx3-3xy2 are of the correct symmetry for phi bonding (3 nodes). There are then other considerations, eg occupancy of the d and f orbitals, the symmetry of the number of other ligands requiring at least some of those orbitals, the diffuse nature and low electron density of f orbitals in the outer regions of the atom where overlap is required for bonding, then pi effects of the ligands eg are they pi donors or pi acceptors My feeling is the f orbitals are too far buried in the atom to be able to bond in a phi fashion even if bonding isn't occupancy or symmetry forbidden
  18. [ReCl8]2- has a metal metal quadruple bond in which one is a delta bond. There is also a chromium acetate dimer, whose exact formula I can't remember with a quadruple bond. It was made in the 1840's I believe and so this is not exactly new.
  19. The copper metal is a one electron reductant The equation Cu +CuCl2 +2Cl- --> 2 [CuCl2]-
  20. I would be careful with potentially coordinating solvents, the pi backdonation is not great. However as my first publication was on the use of Co2(CO)8 I know its pretty soluble in thf. Don't show it any hydroxide though you'll convert it to Co(CO)4- anion
  21. I assume you mean 1 phenylcyclohexene The coupling constant will be important here between the H on the same carbon as the phenyl and the H on the same carbon as the hydroxyl. The phenyl will sit equatorial with the 6 membered ring in the chair. This will place both the afore mentioned Hydrogens in axial positions with a large coupling constant > 8Hz for syn addition. For the antiaddition which obviously won't occur the hydrogens will be axial and equatorial and the coupling will be less 3-5Hz roughly.
  22. Possibly something to do with its band structure and the density of states (My solid state physics isn't great unfortunately)
  23. The methyl groups in the R1 positions stabilise the carbocation by the inductive effect. The aromatic ring stabilises the carbocation by the conjugative effect. The more extensive pi system with the extra phenyl group in R2 position leads to more stabilisation as the positive charge can be delocalised throughout the coplaner two ring pi system
  24. There is a thermodynamic consideration here too as the ester will be the favoured product over the mixed anhydride
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