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Homework Help: Syntesis of [(Ph3P)2CuS2MoS2Cu(PPh3)]

  1. Mar 19, 2006 #1
    Good morning,

    I have problems in equilibrating a synthesis reaction. The pathway is given :
    (NH4)6Mo7024.4H2O +28 H2S+8 NH4OH--> 7(NH4)2MoS4 + 36 H20
    (NH4)2MoS4 (CuCN/KCN/[Pr4N)Br]) --> (Pr4N)2[(CN)CuS2MoS2]
    (Pr4N)2[(CN)CuS2MoS2] + Cu(PPh3)2(NO3) --> [(Ph3P)2CuS2MoS2Cu(PPh3)]

    I don't really see how to equilibrate the 2 last ones and I have also problems to explain really what occurs during this synthesis. I found a contribution from the department of chemistry in Australia. The follwing paragraph explains how works the second reaction :

    Synthesis of (n-Pr4N)2[(CN)CuS2MoS2]

    a solution of KCN (O.64g 9.8mmol) in H2O (7 cm3) is added to a suspension of NH4CuMoS4 (3g 9.8mmol) in H2O (30 cm3) to produce a deep red solution.
    A solution of (n-Pr4N)Br (5.2g 19.6 mmol) in H20 (10cm3) is added dropwise producing a red precipitate.
    The mixture is stirred 15min before the compound which is washed with H2O, EtOH and ether and dried in air, is isolated. (yield 65% 4.35g)

    Ph4As+ et Et4N+ may be prepared in a similar manner. The compounds may also be prepared by combinating equimolar aqueous solution of (NH4)2[MoS4] and [Cu(CN)x ]^(1-x) (produced by combinatingCuSO4.5H20 orCuCN with KCN) followed by the addition of 2-3 equivalents of the quaternary cation.

    Thank you very much for your help.
  2. jcsd
  3. Mar 21, 2006 #2
    Did you unserstand me good... because I come from France and I hope my English il good enough to explain where are my problems :rolleyes:
  4. Mar 21, 2006 #3


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    I don't believe we have a specialist here in organometallic synthesis, in addition I'm not quite sure what you're referring to by "equilibriate."
  5. Mar 22, 2006 #4
    In fact I mean "balance"
  6. Mar 22, 2006 #5


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    balancing the reaction equation stoichiometrically?
  7. Mar 23, 2006 #6
    yes stoichiometrically! otherwise it's not "balancing"
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