40422-14-8

Usage

Uses

n-Propyl-2,2-d2 Alcohol (CAS# 40422-14-8) is a useful isotopically labeled research compound.

Upstream product

• 50-00-0 formaldehyd 
• 3652-84-4 1,1-dideuterio-1-bromoethane 
• 14770-51-5 propionic acid-d3 
• 19136-91-5 (2,2-d₂)-propionic acid 
• 107-19-7 propargyl alcohol 
• 39493-21-5 n-propionaldehyde-2,2-d₂ 

Downstream Products

• 40422-15-9 1-bromopropane-2,2-d2 
• 25493-15-6 1-iodopropane-2,2-d₂ 

Relevant academic research and scientific papers

FT-Raman spectra of n-propanol and selected partially 2H-labelled analogues

Fourier-transform Raman spectra of CH3CH2CH2OH and some of its selectively deuteriated analogues have been obtained. Comparisons of the Raman spectra of the protiated and partially deuteriated species, in conjunction with polarization data, has enabled improved vibrational assignments to be made for the C-H modes. As a result, confirmation of some literature assignments of stretching and bending modes and revision of other tentative assignments for large biopolymer molecules have been proposed.

Inherent asymmetry of constitutionally equivalent methyl groups in the H/D equilibration of n- and i-C3H7Fe(OH)+ complexes

Transiently formed, constitutionally identical methyl groups remain inequivalent in the course of an n-propyl?isopropyl isomerization (see scheme) operative in Fe÷-mediated dehydration of propanols. The reversibility of the β-hydrogen transfer steps is addressed by examination of the H/D equilibration in metastable complexes of Fe+ with a set of selectivity deuterated propanols by using tandem mass spectrometry.

Protonated 1,3,5-cycloheptatriene and 7-alkyl-1,3,5-cycloheptatrienes in the gas phase: Ring contraction to the isomeric alkylbenzenium ions

1,3,5-Cycloheptatriene (1) and various 7-alkyl-1,3,5-cycloheptatrienes (3, 6, 9, 13, and 16-19) were subjected to gas-phase protonation under CI(CH4) and CI(iC4H10) conditions and the MIKE spectra of their [M + H]+ ions were measured. Loss of CH4 from the parent ion [1 + H]+ and almost exclusive loss of C2H4 from the methyl derivative [3 + H]+ indicate ring contraction of the dihydrotopylium ions to protonated toluene (toluenium ions) and protonated ethylbenzene (ethylbenzenium ions), respectively, prior to fragmentation. With increased exothermicity of protonation, ions [3 + H]+ also isomerize to xylenium ions. Similarly, higher protonated n-alkylcycloheptatrienes undergo skeletal isomerization to the corresponding 'chain-elongated' (n + 1)-alkylbenzenium and to the corresponding n-alkyltoluennium ions. Starting with ethyldihydrotropylium ions, a competing isomerization channel is opened giving rise to expulsion of C2H4 from the constituents of the seven-membered ring, as evidenced by deuterium labelling and an unusually high kinetic energy release. Isoalkyl analogues behave in a similar manner with increased hydrogen exchange between the α position of the side chain and the ring.

Mechanism of Propene and Water Elimination from the Oxonium Ion CH3CH=O+CH2CH2CH3

The site-selectivity in the hydrogen transfer step(s) which result in propene and water loss from metastable oxonium ions generated as CH3CH=O+CH2CH2CH3 have been investigated by deuterium-labelling experiments.Propene elimination proceeds predominantly by transfer of a hydrogen atom from the initial propyl substituent to oxygen.However, the site-selectivity for this process is inconsistent with β-hydrogen transfer involving a four-centre transition state.The preference for apparent α- or γ-hydrogen transfer is interpreted by a mechanism in which the initial propyl cation accessible by stretching the appropriate bond in CH3CH=O+CH2CH2CH3 isomerizes unidirectionally to an isopropyl cation, which then undergoes proton abstraction from either methyl group +CH2CH2CH3 CH3CH=O---+CH2CH2CH3 +CH(CH3)2> + CH3CH=CH2>>.This mechanism involving ion-neutral complexes can be elaborated to accommodate the minor contribution of expulsion of propene containing hydrogen atoms originally located on the two-carbon chain.Water elimination resembles propene loss insofar as there is a strong preference for selecting the hydrogen atoms from the α- and γ-positions of the initial propyl group.The bulk of water loss is explicable by an extension of the mechanism for propene loss, with the result that one hydrogen atom is eventually transferred to oxygen from each of the two methyl groups in the complex +CH(CH3)2>.This site-selectivity is strikingly different from that (almost random participation of the seven hydrogen atoms of the propyl substituent) encountered in the corresponding fragmentation of the lower homologue CH2=O+CH2CH2CH3.This contrast is explained in terms of the differences in the relative energetics and associated rates of the cation rearrangement and hydrogen transfer steps.

Reactions of Ionized Dibutyl Ether

The reactions of ionized di-n-butyl ether are reported and compared with those of ionized n-butyl sec-butyl and di-sec-butyl ether.The main fragmentation of metastable (CH3CH2CH2CH2)O+. is C2H5. loss (ca. 85percent), but minor amounts (2-4percent of CH3., C4H7., C4H9., C4H10 and C4H10O are also eliminated.In contrast, C2H5. elimination is of much lower abundance (20 and 4percent, respectively) from metastable CH3CH2CH2CH2OCH(CH3)CH2CH3+. and 2O+., which expel mainly C2H6 and CH3. (35percent-55percent).Studies on collisional activation spectra of the C6H13O+ oxonium ions reveal that C2H5. loss from (CH3CH2CH2CH2)2O+. gives the same product, (CH3CH2CH2CH2+O=CHCH3) as that formed by direct cleavage of CH3CH2CH2CH2OCH(CH3)CH2CH3+..Elimination of C2H5. from (CH3CH2CH2CH2O+. is interpreted by means of a mechanism in which a 1,4-H shift to the oxygen atom initiates a unidirectional skeletal rearrangement to CH3CH2CH2CH2OCH(CH3)CH2CH3+., which than undergoes cleavage to CH3CH2CH2CH2+O=CHCH3 and C2H5..Further support for this mechanism is obtained from considering the collisional activation and neutralization-reionization mass spectra of the (C4H9)2O+. species and the behaviour of the labelled analogues of the (CH3CH2CH2CH2)2O+..The rate of ethyl radical loss is suppressed relative to those of alternative dissociations by deuteriation at the γ-position of either or both butyl substituents.Moreover, C2H5. loss via skeletal rearrangement and fragmentation of the unlabelled butyl group in CH3CH2CH2CH2OCH2CH2CD2CH3+. occurs approximately five times more rapidly than C2H4D. expulsion via isomerization and fission of the labelled butyl substituent.These findings indicate that the initial 1,4-hydrogen shift is influenced by a significant isotope effect, as would be expected if this step is rate limiting in ethyl radical loss.

Unimolecular Reactions of Isolated Organic Ions: the Chemistry of the Oxonium Ions CH3CH2CH2CH2(+)O=CH2 and CH3CH2CH2CH=O(+)CH3

The reactions of the metastable oxonium ions CH3CH2CH2CH2(+)O=CH2 and CH3CH2CH2CH=O(+)CH3 are reported and discussed.Both these isomers of C5H11O(+) expel predominantly CH2O (75 - 90percent of the metastable ion current), a moderate amount of C3H6 (5-15percent), a minor amount of CH3OH (2-8percent) and a very small proportion of H2O (0.5-3percent).All these processes give rise to Gaussian metastable peaks.The kinetic energy releases associated with fragmentation of these oxonium ions are similar, but slightly larger for dissociation of CH3CH2CH2CH=O(+)CH3.The behaviour of labelled analogues confirms that the reactions of CH3CH2CH2CH2(+)O=CH2 and CH3CH2CH2CH=O(+)CH3 are closely related, but subtly different.Elimination of CH2O and C3H6 is intelligible by means of mechanisms involving CH3CH(+)CH2CH2OCH3.This open-chain cation is accessible to CH3CH2CH2CH2(+)O=CH2 by a 1,5-H shift and to CH3CH2CH2CH=O(+)CH3 by two consecutive 1,2-H shifts (or, possibly, a direct 1,3-H shift).The rates of these 1,2-, 1,3- and 1,5-H shifts are compared with one another and also with the rates of CH2O and C3H6 loss from each of the two oxonium ions.The 1,5-H shift that converts CH3CH(+)CH2CH2OCH3 formed from CH3CH2CH2CH=O(+)CH3 into CH3CH2CH2CH2(+)O=CH2 prior to CH2O elimination is essentially unidirectional.In contrast, the corresponding step converting C5H11O(+) ions generated as CH3CH2CH2CH2(+)O=CH2 into CH3CH(+)CH2CH2OCH3 competes effectively with expulsion of CH2O and C3H6.The implications of the latter finding for the degree of concert in the hydrogen transfer and carbon-carbon bond fission steps in alkene losses from oxonium ions via routes that are formally isoelectronic with the retro 'ene' pericyclic process are emphasized.

Unimolecular Reactions of Isolated Organic Ions: Reactions of the Immonium Ions CH2=N+(CH3)CH(CH3)2, CH2=N+(CH3)CH2CH2CH3 and CH2=N+(CH2CH2CH3)2

The reactions of metastable CH2=N+(CH3)C3H7 immonium ions have been investigated by means of 2H-labelling experiments and kinetic energy release measurements.Loss of C3H6, with specific β-H transfer, is the sole channel for dissociation of CH2=N+(CH3)CH(CH3)2.This process gives rise to a Gaussian metastable peak.The isomeric ion, CH2=N+(CH3)CH2CH2CH3, also expels C3H6; however, both α-H and γ-H as well as β-H transfer occurs in this case, and the reaction proceeds with an increased kinetic energy release.The role of ion-neutral complexes in C3H6 loss from CH2=N+(CH3)C3H7 ions is discussed.In addition, CH2=N+(CH3)CH2CH2CH3 eliminates C2H4.This fragmentation yields a broad dish-topped metastable peak, corresponding to a very large kinetic energy release (T1/2 ca. 73 kJ mol-1), and it involves specific and unidirectional γ-H transfer.A potential energy profile summarising the reactions of CH2=N+(CH3)CH2CH2CH3 and CH2=N+(CH3)CH(CH3)2 is constructed.The mechanisms by which immonium ions of this general class eliminate C3H6 and C2H4 have been further probed by studying the behaviour of the higher homologue, CH2=N+(CH2CH2CH3)2.The mechanistic conclusions derived from this work are found to be in excellent qualitative agreement with those of previous studies.

Unimolecular Reactions of Ionised 4-Methoxyheptane

The dissociation of metastable ionised 4-methoxyheptane has been examined by means of extensive 2H-labelling experiments.Only two significant fragmentations are observed, corresponding to loss of ether methanol or propane.Each of these processes involves a hydrogen transfer step in which a pronounced site-selectivity is observed.However, the site-selectivities found for the two fragmentations are distinctly different.Expulsion of methanol, which is characterised by a rather small kinetic energy release, takes place after a unidirectional 1,4-hydrogen transfer to oxygen has occurred; this step is subject to a very large isotope effect.In contrast, loss of propane involves ejection of an intact propyl group, together with an α-hydrogen atom from the second propyl group, via a formal 1,2-elimination.Primary and secondary isotope effects of comparable magnitudes intervene in propane loss from ionised methoxyheptanes in which either or both propyl groups carry 2H-labels on the α-carbon atom.The possibility that ion-neutral complexes are important in the reactions of those C8H18-nDnO+. species is discussed.

Asymmetric catalysis. Mechanism of asymmetric catalytic intramolecular hydrosilation

The mechanism of asymmetric catalytic intramolecular hydrosilation using [Rh(diphosphine)]+ catalysts has been investigated by the use of specifically labeled deuterated substrates. It is concluded that oxidative addition of the silicon hydride

The Mechanism of Water Loss from the Oxonium Ions CH3CH2CH2+ O=CH2 and (CH3)2CH+ O=CH2

Extensive new 2H-labelling results are reported, which pertain to the mechanism of water expulsion from metastable CH3CH2CH2+ O=CH2 and (CH)2CH+ O=CH2 ions.Detailed mechanisms, involving ion-neutral complexes comprising incipient propyl cations coordinated to formaldehyde, propene attached to protonated formaldehyde, or propene and formaldehyde attached to a common proton, are discussed in the light of the labelling data.Loss of positional integrity of the hydrogen and deuterium atoms within the original propyl groups occurs; it is proposed that this takes place via interconversion of the ion-neutral complexes.The crucial step in water elimination appears to be irreversible reorganization of the proton-bound complex (or an ion-neutral complex of protonated formaldehyde and propene) to the open-chain carbonium ion CH3+CHCH2CH2OH.