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| | Hi there. Allow me begin by introducing the writer, her title is Myrtle Cleary. Doing ceramics is what her family and her appreciate. His family lives in South Dakota but his wife wants them to move. Hiring is my occupation.<br><br>My web blog :: [http://www.innovec.com/node/3171 home std test kit] |
| The '''degree of saturation''' (also known as the '''index of hydrogen deficiency (IHD)''' or '''rings plus double bonds'''<ref name="isbn0-9660813-9-0">{{cite book |author=David O. Sparkman |title=Mass Spectrometry Desk Reference |publisher=Global View Pub |location=Pittsburgh |year= |isbn=0-9660813-9-0 |oclc= |doi=|page= 54}}</ref>) formula is used in [[organic chemistry]] to help draw chemical structures. The formula lets the user determine how many rings, double bonds, and triple bonds are present in the compound to be drawn. It does not give the exact number of rings or double or triple bonds, but rather the sum of the number of rings and double bonds plus twice the number of triple bonds. The final structure is verified with use of [[NMR]], [[mass spectrometry]] and [[IR spectroscopy]], as well as qualitative inspection.
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| ==General formula==
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| The formula for degree of unsaturation is shown here
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| :<math>DU = 1 + \frac{1}{2} \sum n_i(v_i-2)</math>
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| where <math>n_i</math> is the number of atoms with [[Valence (chemistry)|valence]] <math>v_i</math>.<ref>{{Cite journal | last1 = Badertscher | first1 = M. | last2 = Bischofberger | first2 = K. | last3 = Munk | first3 = M.E. | last4 = Pretsch | first4 = E. | title = A Novel Formalism To Characterize the Degree of Unsaturation of Organic Molecules | journal = Journal of Chemical Information and Modeling | volume = 41 | pages = 889 | year = 2001 | doi = 10.1021/ci000135o | postscript = <!-- Bot inserted parameter. Either remove it; or change its value to "." for the cite to end in a ".", as necessary. --> | issue = 4}}</ref>
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| That is, an atom that has a valence of ''x'' contributes a total of ''x-2'' to the degree of unsaturation. The result is then halved and increased by 1.
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| ==Rings plus pi bonds formulation==
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| For molecules containing only carbon, hydrogen, monovalent halogens, nitrogen, and oxygen, the formula
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| :<math>Rings + \pi Bonds = C - \frac{H}{2} - \frac{X}{2} + \frac{N}{2}+1\,</math>
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| where C = number of carbons, H = number of hydrogens, X= number of halogens and N = number of nitrogens,<ref>''Organic structural spectroscopy'', chapter 1.</ref> gives an equivalent result. Oxygen and other [[divalent]] atoms do not contribute to the degree of unsaturation, as (2-2) = 0.
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| The degree of unsaturation is used to calculate the number of rings and [[pi bond]]s, where
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| *Rings count as one degree of unsaturation
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| *Double bonds count as one degree of unsaturation
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| *Triple bonds count as two degrees of unsaturation
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| ==See also==
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| *[[Saturation (chemistry)]]
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| ==References==
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| {{Reflist}}
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| Paul R. Young, ''Practical Spectroscopy'' ISBN 0-534-37230-9
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| ==External links==
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| *[http://firstyear.chem.usyd.edu.au/calculators/degree_of_unsaturation.shtml Degree of Unsaturation Calculator]
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| *[http://www.chemie.fu-berlin.de/cgi-bin/molform? Molecular weight and degree of unsaturation calculator]
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| *[http://www.personal.psu.edu/the1/unsatura.htm Degree of Unsaturation]
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| {{DEFAULTSORT:Degree Of Unsaturation}}
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| [[Category:Articles with inconsistent citation formats]]
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| [[Category:Organic chemistry]]
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Hi there. Allow me begin by introducing the writer, her title is Myrtle Cleary. Doing ceramics is what her family and her appreciate. His family lives in South Dakota but his wife wants them to move. Hiring is my occupation.
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