Why does the 31P{1H} NMR spectrum of cis-[Mo(CO)2(dppe)2] show two signals?How many signals would be seen in...
Why does the author believe that the central mass that gas cloud HCN-0.009-0.044 orbits is smaller than our solar system?
Is there any relevance to Thor getting his hair cut other than comedic value?
How to properly claim credit for peer review?
I encountered my boss during an on-site interview at another company. Should I bring it up when seeing him next time?
Equivalent to "source" in OpenBSD?
How can I handle a player who pre-plans arguments about my rulings on RAW?
Make me a metasequence
Linear regression when Y is bounded and discrete
Can you use a beast's innate abilities while polymorphed?
Second-rate spelling
As a new poet, where can I find help from a professional to judge my work?
Does music exist in Panem? And if so, what kinds of music?
Where was Karl Mordo in Infinity War?
What's the difference between a cart and a wagon?
What are these green text/line displays shown during the livestream of Crew Dragon's approach to dock with the ISS?
Where is this triangular-shaped space station from?
Sometimes a banana is just a banana
How to count words in a line
What is the difference between ashamed and shamed?
Casually inserting sexuality
Can chords be played on the flute?
What's the purpose of these copper coils with resistors inside them in A Yamaha RX-V396RDS amplifier?
Why does Starman/Roadster have radial acceleration?
How to speed up a process
Why does the 31P{1H} NMR spectrum of cis-[Mo(CO)2(dppe)2] show two signals?
How many signals would be seen in total in the 13C NMR spectrumpara-dichlorobenzene - number of proton NMR signalsProton NMR signals and ringsWhy are signals of carbon and hydrogen atoms (in NMR spectra) split by coupling to 19F?What does the 129Xe NMR spectrum of XeOF4 look like?Strange 1H-NMR signals/signal ratioDoes this NMR show the carboxy group?Why do the two cycloheptadiene isomers both show four distinct shifts in carbon-13 NMR?Assignment of the 13C NMR spectrum of 1-(ferrocenyl)ethanolPredicted number of signals in proton NMR spectroscopy
$begingroup$
I've tried searching for literature references that explain this, finding only a single reference which refers to the two signals as originating from phosphine environments cis/trans to carbonyls, however I'm having trouble rationalising why this occurs.
I think it might be due to the carbonyl pi orbital electrons deshielding the phosphines with matching orbitals however I'm not sure if this is correct/explained correctly.
Apologies if I've made any errors in this post as it's my first post here.
![Structure of cis-[Mo(CO)2(dppe)2]](https://i.stack.imgur.com/taJNg.png)
inorganic-chemistry stereochemistry nmr-spectroscopy symmetry carbonyl-complexes
edited 2 hours ago
orthocresol♦
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
I've tried searching for literature references that explain this, finding only a single reference which refers to the two signals as originating from phosphine environments cis/trans to carbonyls, however I'm having trouble rationalising why this occurs.
I think it might be due to the carbonyl pi orbital electrons deshielding the phosphines with matching orbitals however I'm not sure if this is correct/explained correctly.
Apologies if I've made any errors in this post as it's my first post here.
inorganic-chemistry stereochemistry nmr-spectroscopy symmetry carbonyl-complexes
edited 2 hours ago
orthocresol♦
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago
add a comment |
$begingroup$
I've tried searching for literature references that explain this, finding only a single reference which refers to the two signals as originating from phosphine environments cis/trans to carbonyls, however I'm having trouble rationalising why this occurs.
I think it might be due to the carbonyl pi orbital electrons deshielding the phosphines with matching orbitals however I'm not sure if this is correct/explained correctly.
Apologies if I've made any errors in this post as it's my first post here.
inorganic-chemistry stereochemistry nmr-spectroscopy symmetry carbonyl-complexes
edited 2 hours ago
orthocresol♦
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I've tried searching for literature references that explain this, finding only a single reference which refers to the two signals as originating from phosphine environments cis/trans to carbonyls, however I'm having trouble rationalising why this occurs.
I think it might be due to the carbonyl pi orbital electrons deshielding the phosphines with matching orbitals however I'm not sure if this is correct/explained correctly.
Apologies if I've made any errors in this post as it's my first post here.
inorganic-chemistry stereochemistry nmr-spectroscopy symmetry carbonyl-complexes
inorganic-chemistry stereochemistry nmr-spectroscopy symmetry carbonyl-complexes
edited 2 hours ago
orthocresol♦
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 2 hours ago
orthocresol♦
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 2 hours ago
orthocresol♦
39.3k7114239
edited 2 hours ago
orthocresol♦
39.3k7114239
edited 2 hours ago
orthocresol♦
39.3k7114239
39.3k7114239
asked 2 hours ago
FunkFunk
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
FunkFunk
232
asked 2 hours ago
FunkFunk
232
232
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Funk is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago
add a comment |
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
In this complex there are two different 31P environments which are not related by symmetry:
![Inequivalent phosphorus nuclei in cis-[Mo(CO)2(dppe)2]](https://i.stack.imgur.com/fCJOl.png)
The two green phosphorus nuclei can be interconverted by a $C_2$ rotation (the rotation axis bisects the OC–Mo–CO angle), and so can the purple ones, but green and purple cannot be interconverted.
As extra proof, consider that the green P is cis to both carbonyl ligands whereas the purple P is cis to one and trans to the other.
They therefore have different chemical shifts and in the spectrum you would expect to see two different peaks. Presumably they would show coupling to each other, so I would expect two triplets, if we ignore satellites from all other nuclei (e.g. 13C).
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "431"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Funk is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f110406%2fwhy-does-the-31p1h-nmr-spectrum-of-cis-moco2dppe2-show-two-signals%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
In this complex there are two different 31P environments which are not related by symmetry:
The two green phosphorus nuclei can be interconverted by a $C_2$ rotation (the rotation axis bisects the OC–Mo–CO angle), and so can the purple ones, but green and purple cannot be interconverted.
As extra proof, consider that the green P is cis to both carbonyl ligands whereas the purple P is cis to one and trans to the other.
They therefore have different chemical shifts and in the spectrum you would expect to see two different peaks. Presumably they would show coupling to each other, so I would expect two triplets, if we ignore satellites from all other nuclei (e.g. 13C).
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
$endgroup$
add a comment |
$begingroup$
In this complex there are two different 31P environments which are not related by symmetry:
The two green phosphorus nuclei can be interconverted by a $C_2$ rotation (the rotation axis bisects the OC–Mo–CO angle), and so can the purple ones, but green and purple cannot be interconverted.
As extra proof, consider that the green P is cis to both carbonyl ligands whereas the purple P is cis to one and trans to the other.
They therefore have different chemical shifts and in the spectrum you would expect to see two different peaks. Presumably they would show coupling to each other, so I would expect two triplets, if we ignore satellites from all other nuclei (e.g. 13C).
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
$endgroup$
add a comment |
$begingroup$
In this complex there are two different 31P environments which are not related by symmetry:
The two green phosphorus nuclei can be interconverted by a $C_2$ rotation (the rotation axis bisects the OC–Mo–CO angle), and so can the purple ones, but green and purple cannot be interconverted.
As extra proof, consider that the green P is cis to both carbonyl ligands whereas the purple P is cis to one and trans to the other.
They therefore have different chemical shifts and in the spectrum you would expect to see two different peaks. Presumably they would show coupling to each other, so I would expect two triplets, if we ignore satellites from all other nuclei (e.g. 13C).
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
$endgroup$
In this complex there are two different 31P environments which are not related by symmetry:
The two green phosphorus nuclei can be interconverted by a $C_2$ rotation (the rotation axis bisects the OC–Mo–CO angle), and so can the purple ones, but green and purple cannot be interconverted.
As extra proof, consider that the green P is cis to both carbonyl ligands whereas the purple P is cis to one and trans to the other.
They therefore have different chemical shifts and in the spectrum you would expect to see two different peaks. Presumably they would show coupling to each other, so I would expect two triplets, if we ignore satellites from all other nuclei (e.g. 13C).
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
edited 2 hours ago
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
answered 2 hours ago
orthocresol♦orthocresol
39.3k7114239
39.3k7114239
add a comment |
add a comment |
Funk is a new contributor. Be nice, and check out our Code of Conduct.
Funk is a new contributor. Be nice, and check out our Code of Conduct.
Funk is a new contributor. Be nice, and check out our Code of Conduct.
Funk is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Chemistry Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f110406%2fwhy-does-the-31p1h-nmr-spectrum-of-cis-moco2dppe2-show-two-signals%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
I just realised why, I'm a total idiot 😂 - I blame this on my lack of sleep. To ask a question that requires an actual answer @orthocresol I see you added a far better representation of the complex, do you have any tips on how to draw better looking chelating ligands?
$endgroup$
– Funk
2 hours ago
$begingroup$
Not really! I just drew a regular octahedral complex in ChemDraw (from Templates > Stereocentres), made it a bit bigger (or else the PPh2 clashes into the CO), filled in the PPh2's and CO's, then drew a few bonds between phosphorus. Yours was perfectly fine, just a bit large, and I was drawing it for my answer anyway so it was trivial to add it into the question itself.
$endgroup$
– orthocresol♦
2 hours ago
$begingroup$
Are you using ChemDraw's default document settings? If I try to follow a similar process the ligand bonds end up being too long so I end up with disproportionately large ligands.
$endgroup$
– Funk
2 hours ago
$begingroup$
Nope, for all the diagrams on SE, I use a version of the Trauner group ChemDraw template where everything is scaled by 0.75x. If you use the ACS Document 1996 template in ChemDraw it gives stuff which look pretty similar, so you could try that out.
$endgroup$
– orthocresol♦
2 hours ago