Ethyl Methyl Ether Research Articles

Electron-Induced Formation of Ethyl Methyl Ether in Condensed Mixtures of Methanol and Ethylene.

Electron-induced reactions in condensed mixtures of ethylene (C2H4) and methanol (CH3OH) lead to the formation of ethyl methyl ether (EME, C2H5OCH3), as shown by post-irradiation thermal desorption spectrometry (TDS). In contrast to the electron-induced reaction between water (H2O) and C2H4, product formation as a consequence of proton transfer following electron attachment (EA) to C2H4 is not observed in the analogous reaction between CH3OH and C2H4. However, a resonant process centered around 5.5 eV and a threshold-type increase of product yield starting at 9 eV is observed. On the basis of the presence and absence of particular side products after irradiation of the mixture as well as of the pure parent compounds, reaction mechanisms related to the two energy regimes are proposed. Below the ionization threshold of the reactants, dissociative electron attachment (DEA) to CH3OH triggers the reaction sequence by producing reactive methoxy radicals, which attack neighboring C2H4 molecules. The resulting adduct then abstracts a hydrogen atom to yield EME. Above but near the ionization threshold, electron impact ionization (EI) produces primarily intact molecular cations, which drive the reaction by converting the repulsive Coulomb force between the high electron densities at the reactive sites of the two neutral parent species into an attractive force. This again induces the formation of an adduct between the two reactants that rearranges to the product EME. Fragmentation of the molecular CH3OH+• cation into CH3O+, however, may provide an additional reaction pathway toward EME. In this scenario, CH3O+ attacks a neighboring C2H4 molecule. The resulting adduct is then neutralized by a thermalized electron and abstracts a hydrogen atom from a nearby CH3OH molecule to yield EME.

Hydrogen abstraction by NO2 from asymmetric methyl ethers: A theoretical investigation

Hydrogen abstraction by NO2 from asymmetric methyl ethers by NO2 is theoretically investigated based on first-principles calculations in order to constrain their combustion models, including methyl ethyl ether(MEE), methyl n-propyl ether (MNPE), methyl i-propyl ether (MIPE), methyl n-butyl ether (MNBE), and methyl t-butyl ether (MTBE). We obtain the rate constants and branching ratios at 500–2000 K, and the dependence of reactivity on ether sizes and the reaction sites on the ethers. The cis-HONO channel is the most important one, followed by the HNO2 and trans-HONO channels. On the hand, the size of alkyl and the reaction site significantly affect the reactivity. Hydrogen abstraction mainly occurs at the C site (adjacent to the ether bond) of the long-chain alkyl. Moreover, the linear Bell-Evans-Polanyi correlation is observed for the hydrogen abstraction reactions between the asymmetric methyl ether and NO2.

Constraining the Molecular Complexity in the Interstellar Medium—The Formation of Ethyl Methyl Ether (CH3OCH2CH3) in Star-forming Regions

Abstract We report the first confirmed synthesis of ethyl methyl ether (EME, CH3CH2OCH3) within astrophysical model ices containing water (H2O) and methane (CH4) exposed to ionizing radiation at ultra-low temperatures of 5 K. EME (also known as methoxyethane), was recently observed toward Orion KL and currently is the largest confirmed oxygen-bearing molecule found in the interstellar medium. Exploiting isomer-selective photoionization (PI) of the subliming molecules in the temperature-programmed desorption phase at 10.49, 9.92, and 9.70 eV, coupled with reflectron time-of-flight mass spectrometry and isotopic substitution experiments (H2 18O–CH4), the detection of fragment ions of EME at m/z = 45 (C2H5O+) and m/z = 59 (C3H7O+), and probing the proton transfer in subliming ethanol–EME complexes via m/z = 61 (C3H9O+), the present study reveals that EME can be formed from suprathermal reactions initiated by cosmic rays and secondary electrons generated within astrophysical ices. The detection of EME in our experiments represents a significant advance in the understanding of formation pathways of complex organic molecules present in hot cores and helps to constrain astrochemical models on the formation of such species within molecular clouds.

A DFT study on the catalytic ability of aluminum doped graphene for the initial steps of the conversion of methanol to gasoline

Abstract The detailed mechanisms for the initial steps of methanol to gasoline (MTG) process, up to 3-carbons products, were studied using DFT calculations and aluminum doped graphene (AG) as catalyst. During the study, the structures of the reactants, products, intermediates and transition states were optimized and confirmed by frequency and IRC calculations. The most of steps are energetically affordable with acceptable barrier energies. The best route (by considering both thermodynamic and kinetic values) was producing ethanol as intermediate and 1-propanol as 3-carbons product. In addition, the production of dimethyl ether and ethylene as intermediates and methyl ethyl ether as a product were energetically possible. This work proved the catalytic ability of AG for MTG process and the results could be employed in the future experimental studies regard to the developments of new catalysts for MTG process.

On the Synthesis of Chocolate Flavonoids (Propanols, Butanals) in the Interstellar Medium.

Complex organic molecules are ubiquitous in star- and planet-forming regions as well as on comets such as on 67P/Churyumov-Gerasimenko, but their origins have remained largely unexplained until now. Here, we report the first laboratory detection of distinct C3 H8 O (propanol, methyl ethyl ether) and C4 H8 O (n-butanal, i-butanal) isomers formed within interstellar analog ices through interaction with ionizing radiation. This study reveals that complex organics with propyl (C3 H7 ) and butyl (C4 H9 ) groups can be synthesized easily in deep space and may act as key evolutionary tracers of a cosmic ray driven non-equilibrium chemistry in low temperature interstellar ices at 10 K. These processes are of vital importance in initiating a chain of chemical reactions leading to complex organics-some of which are responsible for the flavors of chocolate-not only in the interstellar medium, but also on comet 67P/Churyumov-Gerasimenko.

Green synthetic route for perfumery compound (2-methoxyethyl) benzene using Li/MgO catalyst

Ethers are one of the most prominent compounds among perfumery chemicals. (2-Methoxyethyl) benzene commonly known as phenyl ethyl methyl ether (PEME) is widely used in flavour and fragrance industries. Conventionally, synthesis of PEME involves the use of hazardous and polluting chemicals, which in turn affects the purity of perfumery compound. Thus, developing a green route to synthesise PEME without any hazardous chemicals is desirable. In the current work, a new process is developed for the synthesis of PEME using solid base catalysts including MgO and Li/MgO (with different loadings of lithium) and dimethyl carbonate (DMC) as a methylating agent as well as a solvent. Different kinetic parameters were studied to achieve the optimum yield of the desired product. At optimum reaction conditions i.e., 1000 rpm of speed, $$1.33 \times 10^{-2}\,\hbox {g/cm}^{3}$$ of catalyst loading, 1:10.5 mole ratio (2-Phenyl ethanol: DMC), $$180\,^{\circ }\hbox {C}$$ , 95% conversion of 2-phenyl ethanol with 98% selectivity of PEME was achieved. A detailed kinetic model was also developed and apparent activation energy for the reaction was calculated as 11.93 kcal/mol. SYNOPSIS:2-Methoxyethyl benzene commonly known as phenyl ethyl methyl ether (PEME) was selectively synthesised in high yields from 2-phenyl ethanol (2-PE) and dimethyl carbonate (DMC) as a methylating agent with carbon dioxide and methanol as co-products. Li/ MgO with different loadings of Li was studied and 0.1% Li/MgO was found to be the best catalyst among the screened catalysts. PEME has wide applications as perfumery compound.

Proton-induced reactions of [2.2]-paracyclophane in the gas phase. A study by FT-ICR-spectrometry and DFT calculation.

The reactions of the [2-2]-paracyclophane 1 and the [2-2]-metaparacyclopane 2 in the gas phase after protonation by CI(CH4) or CI(I-C4H10) were studied by FT-ICR mass spectrometry. The ions C16H17+ produced in the external ion source of the FT-ICR instrument were transferred into the ICR cell containing the neutral reactant, and the reactions were analyzed measuring the efficiency of the transfer of a proton to a series of bases with known proton affinity and gas phase basicity as well as the efficiency of the ion-molecule reaction with ethyl vinyl ether. Both reaction types show that the ions C16H17+ produced by chemical ionization (CI) consist of two sets of isomeric ions A and B which exhibit distinctly different behavior on deprotonation and of the reaction with ethyl methyl ether. Isomer(s) A (about 65% of the ion population) react efficiently with this vinyl ether by an addition/elimination process typical of primary and secondary benzylic carbenium ions, while isomer B (about 35% of the ion population) undergoes only an ineffective deprotonation by the vinyl ether. By bracketing deprotonation, it is shown that A is actually composed of two isomers A1 and A2 with slightly different proton affinity and gas phase basicity. These two ions have been identified using CA-mass spectrometry as protonated 3-phenethylstyrene (A1) and protonated 4-phenethylstyrene (A2). The CA-mass spectrum of the isomer B indicated that these ions C16H17+ correspond to protonated 1-(ethyl phenyl)-1-phenyl-ethene. This agrees with the rather strong basicity of the conjugated base of ions B, which results in a slow deprotonation. A protonated 1-(ethyl phenyl)-1-phenyl-ethene can arise from a protonated 2-phenethylstyrene by H- and subsequent phenyl shifts, but requires the preceding rearrangement of the protonated [2.2]-paracyclophane into the protonated isomer "[2.2]-orthocyclophane" - the 1,5-dibenzocyclooctadiene. The possibility of such a deep-sited rearrangement was studied by the computation of the relevant reaction routes applying DFT-methods at the level B3LYP/6-311+g(3d,2p)//B3LYP/3-21g) to analyze the reaction mechanisms.

Physicochemical Properties of Dialkyl Ethers

Ethylene glycol diethyl ether (1,2-diethoxyethane: DEE) is dialkyl ethers of ethylene glycol. The solubility of lithium salts in DEE is much less than that in ethylene glycol dimethyl ether (1,2-dimethoxyethane: DME) and ethylene glycol ethyl methyl ether (1-ethoxy-2-methoxyethane: EME). Partial fluorination of DEE increases the polarity. We have investigated the effect of the partial fluorination on the physical and electrochemical properties of DEE in some detail. The mass densities decreased in the order of decreasing the molar mass: tetrafluorinated DEE (FETFEE) > trifluorinated DEE (ETFEE) > monofluorinated DEE (EFEE) (≈ diethyl carbonate (DEC)) > DEE. The molar concentration of FETFEE was higher than that of ETFEE in spite of the large molar size: DEC > EFEE > DEE > FETFEE > ETFEE. The relative permittivity and viscosity of FETFEE were higher than those of ETFEE and EFEE: FETFEE > ETFEE ≈ EFEE > DEE > DEC for the relative permittivity and FETFEE > EFEE > ETFEE > DEC > DEE for the viscosity. The kinematic viscosity of ETFEE was as low as that of DEE above 50 °C. The partial fluorination of DEE improved the solubility of LiPF6. The electrolytic conductivity of 1 mol dm−3 LiPF6/FETFEE was lower than that of 1 mol dm−3 LiPF6/EFEE, but higher than that of 1 mol dm−3 LiPF6/ETFEE. The partial fluorination can increase the ability of the solvent molecules to form hydrogen bonds. The fluoromethyl group may serve as an anion-attracting group. The use of an EC−FETFEE equimolar binary mixture suppressed the discharge capacity fading at high cycle numbers.

Design and synthesis of some tricyclic pyrimidines and triazines via cycloaddition and intermolecular cyclization of cyclic amidine

The cyclic amidine 3 was used as a precursor in this research, which was synthesized by chlorination of compound 1, followed by ring closure with hydrazine hydrate. Cyclization of amidine compound 3 with acetylacetone, ethyl cyanoacetate, chalcone analogue 6 and benzylidenemalononitrile (8) tolerated the expected tricyclic pyrimidines 4, 5, 7 and 9, respectively. Reaction of 3 with ammonium thiocyanate followed by cyclization of the product 10 with DMF, ethyl chloroformate and chloroacetyl chloride afforded triazine derivatives 11–13, respectively. Nucleophilic substitution of the later compound with EtONa gave ethyl methyl ether derivative 14. The benzamide derivative 15 was obtained by reaction of 3 with benzoylisothiocyanate or benzoylation of compound 10 with benzoyl chloride. Finely, heterocylization of 15 in the presence of Et3N gave the triazine derivative 16. 6-(4-Chlorophenyl)-4-(4-isopropylphenyl)-1H-pyrazolo[3,4-b]pyridin-3-amine (3) was used as the starting material for the synthesis of pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine and pyrido[2′,3′:3,4]pyrazolo[1,5-a][1,3,5]triazine derivatives via cycloaddition and intermolecular cyclization reactions.

Steroid-AuI -NHC Complexes: Synthesis and Antibacterial Activity.

A series of gold(I) pioneer complexes bearing N-heterocyclic carbenes and steroid derivatives (ethynylestradiol and ethisterone) with the generic formula [Au(R2 -imidazol-2-ylidene)(steroid)] (where R=CH3 or CH2 CH2 OCH3 ) were synthesized, and the X-ray structure of a rare of gold(I)-estradiol derivative is discussed. Toxicity studies reveal notable antibacterial activity of the gold-based compounds, which is significantly increased in vivo by the presence of the estradiol unit. Toxicity profiling was estimated in vitro versus Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, and in vivo on Galleria mellonella larvae against E. coli.

DFT study on the adsorption of diethyl, ethyl methyl, and dimethyl ethers on the surface of gallium doped graphene

In this study, we used density functional theory (DFT) to search on the adsorption properties of three important compounds of ether family; diethyl ether (DEE), ethyl methyl ether (EME), and dimethyl ether (DME) on the surface of Gallium doped graphene (GaG). We used three functionals (B3LYP, wb97xd, and MPW1PW91) for optimization and calculation of adsorption energy. After fully optimization, we scrutinized on the charge allocations on the adsorbed ethers as well as GaG (at the area of interaction) based on natural bond orbitals (NBO). Besides, we have calculated the amount of charge transfer upon adsorption of each analyte. We revel that GaG is an ideal adsorbent for chemisorption of all above-mentioned ethers. There is a little difference between the values of adsorption; −123.5, −120, and −118.3kJ/mol (based on wb97xd) for DEE, EME, and DME, respectively. We found significant changes in the electronic structure of both adsorbent and adsorbate upon adsorption. Moreover, results of charge analyses confirm GaG is a p-type semiconductor.

Atmospheric Chemistry of CH3CH2OCH3: Kinetics and Mechanism of Reactions with Cl Atoms and OH Radicals

ABSTRACTThe atmospheric chemistry of methyl ethyl ether, CH3CH2OCH3, was examined using FT‐IR/relative‐rate methods. Hydroxyl radical and chlorine atom rate coefficients ofk(CH3CH2OCH3+OH) = (7.53 ± 2.86) × 10−12cm3molecule−1s−1andk(CH3CH2OCH3+Cl) = (2.35 ± 0.43) × 10−10cm3molecule−1s−1were determined (297 ± 2 K). The Cl rate coefficient determined here is 30% lower than the previous literature value. The atmospheric lifetime for CH3CH2OCH3is approximately 2 days. The chlorine atom–initiated oxidation of CH3CH2OCH3gives CH3C(O)H (9 ± 2%), CH3CH2OC(O)H (29 ± 7%), CH3OC(O)H (19 ± 7%), and CH3C(O)OCH3(17 ± 7%). The IR absorption cross section for CH3CH2OCH3is (7.97 ± 0.40) × 10−17cm molecule−1(1000–3100 cm−1). CH3CH2OCH3has a negligible impact on the radiative forcing of climate.

Characterization of the Cathode Electrolyte Interface in Lithium Ion Batteries by Desorption Electrospray Ionization Mass Spectrometry.

The solid electrolyte interface (SEI) formed via electrolyte decomposition on the anode of lithium ion batteries is largely responsible for the stable cycling of conventional lithium ion batteries. Similarly, there is a lesser-known analogous layer on the cathode side of a lithium ion battery, termed the cathode electrolyte interface (CEI), whose composition and role are debated. To confirm the existence and composition of the CEI, desorption electrospray ionization mass spectrometry (DESI-MS) is applied to study common lithium ion battery cathodes. We observe CEI formation on the LiMn2O4 cathode material after cycling between 3.5 and 4.5 V vs Li/Li(+) in electrolyte solution containing 1 M LiPF6 or LiClO4 in 1:1 (v/v) ethylene carbonate (EC) and dimethyl carbonate (DMC). Intact poly(ethylene glycol) dimethyl ether is identified as the electrolyte degradation product on the cathode surface by the high mass-resolution Orbitrap mass spectrometer. When EC is paired with ethyl methyl carbonate (EMC), poly(ethylene glycol) dimethyl ether, poly(ethylene glycol) ethyl methyl ether, and poly(ethylene glycol) are found on the surface simultaneously. The presence of ethoxy and methoxy end groups indicates both methoxide and ethoxide are produced and involved in the process of oligomerization. Au surfaces cycled under different electrochemical windows as model systems for Li-ion battery anodes are also examined. Interestingly, the identical oligomeric species to those found in the CEI are found on Au surfaces after running five cycles between 2.0 and 0.1 V vs Li/Li(+) in half-cells. These results show that DESI-MS provides intact molecular information on battery electrodes, enabling deeper understanding of the SEI or CEI composition.

Characterization of the Cathode Electrolyte Interface in Lithium Ion Batteries By Desorption Electrospray Ionization Mass Spectrometry (DESI-MS)

The solid electrolyte interface (SEI) formed via electrolyte decomposition on the anode of lithium ion batteries is largely responsible for the stable cycling of conventional lithium ion batteries. Similarly, there is a lesser-known analogous layer on the cathode side of a lithium ion battery, termed the cathode electrolyte interface (CEI), whose composition and role are debated. To confirm the existence and composition of the CEI, desorption electrospray ionization mass spectrometry (DESI-MS) is applied to study common lithium ion battery cathodes. As a surface ionization method, DESI does not require matrix addition or high-energy radiation, reducing the perturbation of the surface. We observe CEI formation on both LiMn2O4 and LiCoO2 after running half-cells using 1 M LiPF6 or LiClO4 in ethylene carbonate (EC) with dimethyl carbonate (DMC). Intact poly(ethylene glycol) dimethyl ether is identified as the electrolyte degradation product on the cathode surface by the high mass-resolution Orbitrap mass spectrometer after five cycles between 3.5 and 4.5 V vs. Li/Li+. When EC is paired with ethyl methyl carbonate (EMC), poly(ethylene glycol) dimethyl ether and poly(ethylene glycol) methyl ethyl ether are found on the surface simultaneously. The presence of ethoxy and methoxy end groups indicates both methoxide and ethoxide are produced and involved in the process of oligomerization. Au surfaces cycled under different electrochemical windows as model systems for Li-ion battery anodes are also examined. Interestingly, the identical oligomeric species to those found in the CEI are found on Au surfaces after running five cycles between 2.0 and 0.2 V vs. Li/Li+ in half-cells. These results show that DESI-MS provides intact molecular information on battery electrodes, enabling deeper understanding of the SEI or CEI composition. Figure 1

Hydrogen Abstraction from Fluorinated Ethyl Methyl Ether Systems by OH Radicals

A systematic computational investigation of hydrogen abstraction by OH from the full series of fluorinated ethyl methyl ethers (EME) containing at least one H and one F, C2HnX5-nOCHmX3-m (n=0–5, m=0–3; and n=m=0 not allowed), including 147 reactants and 469 transition states, has been carried out, employing the MP2/6-31G(d) level of theory. Results for optimized geometries, including evidence of intramolecular hydrogen bonding in transition states, and barrier heights are presented. Trends pertaining to the number of fluorines substituted, key bond lengths, barrier heights, and key bond angles were found with good correlations and were investigated. An increase in the number of F increases the barrier height of the reaction. An increase in some parameters such as C–H length of TS, relative change in C–H from reactants to TS, ∠COC of reactants, ∠HOH in the TS, and relative change in ∠HOH between TS and free water bond angle also correlates with increased barrier height. An increase in other parameters like C–H length in the reactants and hydrogen bonding can decrease the barrier height.

Searching for trans ethyl methyl ether in Orion KL.

We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm-2 and ≤(1.0 ± 0.2)× 1015 cm-2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion.

Al-doped graphene as modified nanostructure sensor for some ether molecules: Ab-initio study

We investigated the adsorption of some famous ether molecules: Diethyl ether (DEE), Ethyl methyl ether (EME), and Dimethyl ether (DME) on the surface of pristine as well as Al-doped graphene using density functional theory (DFT) calculations to explore a highly sensitive sensor for them. Compared with the pristine graphene, the Al-doped graphene gives high adsorption energy and short intra-molecular bond length and more charge transfer upon interaction with these molecules which are correspond to chemisorptions while the adsorption of these molecules on pristine graphene release insignificant energy which correspond to very weak interaction between them. Moreover we used orbital analysis including the density of states (DOS) to find out the possible orbital hybridization between these molecules and pristine as well as Al-doped graphene. Based on our results, Al-doped graphene has potential to be a new nanostructure sensor for DEE, EME and DME gas molecules.

THE SEARCH FOR A COMPLEX MOLECULE IN A SELECTED HOT CORE REGION: A RIGOROUS ATTEMPT TO CONFIRM TRANS-ETHYL METHYL ETHER TOWARD W51 e1/e2

An extensive search has been conducted to confirm transitions of \textit{trans}-ethyl methyl ether (tEME, C$_2$H$_5$OCH$_3$), toward the high mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory (ARO) at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by \citet{FuchsSpace}. Additionally, reevaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 - 30 mK, yielding an upper limit of the tEME column density of $\leq$ 1.5 $\times$ 10$^{15}$ cm$^{-2}$. This would make tEME at least a factor 2 times less abundant than dimethyl ether (CH$_3$OCH$_3$) toward W51 e1/e2. We also performed an extensive search for this species toward the high mass star forming region Sgr B2(N-LMH) with the NRAO 100 m Green Bank Telescope (GBT). No transitions of tEME were detected and we were able to set an upper limit to the tEME column density of $\leq$ 4 $\times$ 10$^{14}$ cm$^{-2}$ toward this source. Thus, we are able to show that tEME is not a new molecular component of the interstellar medium and that an exacting assessment must be carried out when assigning transitions of new molecular species to astronomical spectra to support the identification of large organic interstellar molecules.

Discussions of Mass Transfer Behaviors Between VOCs and TEG Solutions by Surface Tension and Equilibrium Process

In order to discuss mass transfer behaviors between volatile organic compound (VOC) and triethylene glycol (TEG) solutions affected by surface tension and equilibrium process. The packed-bed absorption system and the equilibrium system were designed. TEG solution was chosen as the working solution in this study, and the tested VOCs included methanol, methyl ethyl ketone (MEK), toluene, and ethyl ether. Experimental results showed that the order of absorption performances was methanol, MEK, toluene, and ethyl ether in the initial concentrations of VOCs were 24.05% mol and 14.50% mol. This result agreed with the prediction by the equilibrium concentration.

Controlled ring‐opening polymerization of trimethylene carbonate and access to PTMC‐PLA block copolymers mediated by well‐defined N‐heterocyclic carbene zinc alkoxides

Four novel Zinc–NHC alkyl/alkoxide/chloride complexes (4, 5, 9 and 9′) were readily prepared and fully characterized, including X‐ray diffraction crystallography for 5 and 9′. The reaction of N‐methyl‐N′‐butyl imidazolium chloride (3.HCl) with ZnEt2 (2 equiv.) afforded the corresponding [(CNHC)ZnCl(Et)] complex (4) via a protonolysis reaction, as deduced from NMR data. The alcoholysis of 4 with BnOH led to quantitative formation of the dinuclear Zn(II) alkoxide species [(CNHC)ZnCl(OBn)]2 (5), as confirmed by X‐ray diffraction analysis. The NMR data are in agreement with species 5 retaining its dimeric structure in solution at room temperature. The protonolysis reaction of N‐(2,6‐diisopropylphenyl)‐N′‐ethyl methyl ether imidazolium chloride (8.HCl) with ZnEt2 (2 equiv.) yielded the [(CNHC)ZnCl(Et)] species 9. The latter was found to be reactive with CH2Cl2 in solution and to cleanly convert to the corresponding Zn(II) dichloride [(CNHC)ZnCl2]2 (9′), whose molecular structure was also elucidated using X‐ray diffractometry. Unlike Zn(II)–NHC alkoxide species 1 and 2, which contain a NHC flanked with an additional N‐functional group (i.e. thioether and ether, respectively), the Zn(II) alkoxide species 5 incorporates a monodentate NHC ligand. The Zn(II) complexes 1, 2 and 5 were tested in the ring‐opening polymerization (ROP) of trimethylene carbonate (TMC). All three species are effective initiators for the controlled ROP of trimethylene carbonate, resulting in the production of narrow disperse PTMC material. Initiator 1 (incorporating a thioether moiety) was found to perform best in the ROP of TMC. Notably, the latter also readily undergoes the sequential ROP of TMC and rac‐LA in the presence of a chain‐transfer agent, leading to well‐defined and high‐molecular‐weight PTMC/PLA block copolymers. Copyright © 2014 John Wiley & Sons, Ltd.