remember 1b Flashcards

(43 cards)

1
Q

CO ligand gives how many electrons

A

2

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2
Q

co ligand has whag dharge

A

0 neutral

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3
Q

CP ligand has what charge

A

anionic charge!!

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4
Q

alkene as a ligand charge

A

0

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5
Q

number of mm bonds when predicting shapes

A

NEED - HAVE / 2 !!!

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6
Q

Metal carbonyl + Na/Hg

A

bc Na is positive,, the complex will be negative

u will also half the complexxx so from 2 metals to 1 and from 8 ligands to 4 etc

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7
Q

negative nmr ppm means

A

hydride is formed

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8
Q

a hydride has a low pka when

A

its a strong acid

mraning its conjugate base is stable

normally bc theres good pi acceptor ligands aka CO

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9
Q

when can pka of a hydrode increase

A

when the conjugate base is less stable

aka theres a sigma donor here

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10
Q

M2CO8,, what metal is itttt

A

Co: 2e- x 8 = 16e- for both metals therefore 8 per metal

18-8 = 10e-
so 10e- metal butttttt,, we also need to think that theres a mm bond,, so 10 is with the mm bond adding one e-,, so withut the metal metal bond there would be 9e-

look for a TM with 9e-!!!

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11
Q

counting valence electrons in a complex

A

metal and contributio from ligands

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12
Q

contribution of alkene

A

2 electronsss

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13
Q

when asked to guess reactions what should we do, aka we get a complex and a ligand

A

count how many e- we have in the complex
ligand and metal and charge

then see if its 18e- or 16e- etccc

then look at the incoming ligand

if its a halogen its probs a SN2 type thing
if its 16e- complex then probs dissociative subs,, if its 18e- probs associative subs etc.

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14
Q

can an oxidation state be neagtive

A

yus

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15
Q

when finding the valence electron count what do we need to do first

A

we need to find the oxidation state of the metal

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16
Q

if H is a ligand what do we need to remember

A

rememebr that its a H-

so a hydride

so it gives 2e-

and it affects the oxidation state of the metal by -1. so wed get a +1 OS.

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17
Q

if our ligand is an alkene,, and our complex is 16e- and has a H as a ligand what happens

A

migratory insertion reaction

we add the alkene cis to the H then we migrate the H onto the alkene to form an alkane lowkssss

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18
Q

CH2CH3 as. aligand description

A

its -1 charge therefore it affects the metals oxidation state

19
Q

what else should we look at the ligands for when were asked to guess the reaction

A

look for beta hydrogens bc beta hydride elimination may occurrrrr

one of the ligands cis to the b hydrogen needs to be removed thoo so we have a vacant site yay

20
Q

if the ligands approaching is a CO what do we need to think of

A

we need to think of migratory insertion!!!

aka Me will migrate onto a CO and then the new CO will attack the vacant site

21
Q

when we wanna rate ligands based on their pi acceptor abilities what should we look for.

A

POSITIVE CHARGE

ELECTRONEGATIVE

LARGE // DIFFUSE ORBITALS : overlap with metals d orbitals better!!

(-) charge will be very bad

the top 3 thin gs lower the energy of the Pi* which is wherre the m bb into

22
Q

5 lkgand complex undergoing oxidative addition with H2 approaching but one of the OG ligands is a Cl

A

add a H and replace Cl

23
Q

Mn2 CO10 dimer + HCl what reaction is this and what do we get as products

A

oxidative addition heterolytic version

we split them up obvs and one will get the H and the other will get the Cl

24
Q

when migratory inertion occurs where do things go

A

the migrated ligand goes from the M to the metal again, aka the migrated ligand always tries to go between the M-L of a diff liganddd

25
when we see CO what should we think of
migratory insertion perhaps the co comes between the M and the L
26
CH3 and CH2CH3,, which one will the CO migrate between
the CH3 bc less hinderedddd
27
H and alkene cis with just reflux
migrate the alkene to form an alkane then kick it off via reductive elimination
28
when theres a H or Cl in a complex and we are elecron counting what should we do
remeber H and Cl affect ur oxidation state
29
when doing the 18e- rule remmeer what
outside = inside CH3 =-1 charge H = -1 charge halogen = -1 charge
30
alkene acc charge when cwere counting e-
0 its neutral
31
CP charge when counting e-
-1 anionic
32
Cp e-c count when counting e-
5 based in the n number
33
18e- but trigonal bipyramidal + H2 as an incoming ligand
oxidative additgion of just one H try keep trigonal bipyramidal,, maybe swap H for smt with the same e- contribution and charge aka if theres a Cl replace it with H.
34
metal complex with reflux
- H and alkene to alkane
35
ACTUAL: OA
- H2 or R-X ligand incoming - d8-d10 - low oxidation state - less than 18 // move to allow it ligand incoming = sigma bond
36
ACTUAL: migratory insertion
MR CIS to CO or ALKENE CO // ALKENE migrates on smallest alkane!!!! aka ch3 over ch2ch3
37
ALKENE MIGRATION
Alkene cis to MR or H will move and get turned into an alkane normally no ligand incoming just reflux
38
B hydride elimination
- need beta hydride and vacant spot on the metal forms a MH bond and an alkene
39
REDUCTIVE ELIMINATION
- 18elec trons - metal has high oxidation state aka +3 etc
40
which one will have the larger IR vib freq,, what do we need to remember
more e- rich metal = more bb = weaker bond = lower vib frequency - negative oxidation state = more electron rich = more bb = weaker bond = lower frequency - POMe = good pi acceptor so competes against CO for e-,, less bb into CO - more sigma donors = more e- into CO = more bb = lower vib freq - less CO = more concentrated bb = weaker bond = smaller vib freq - rhs metal = more electronegative = less likely to give e- = less bb = larger vib freq
41
rememeber cp = -1 charge
42
if the metal is anionic,, aka - what do we do.
sn2 aka we atatck the C,, dont add the halogen,, then do the next step they tell us to do
43