The gas phase Smiles rearrangement of anions PhO(CH(2))nO(-) (n = 2-4): A joint theoretical and experimental approach

A combination of experimental data [using 18O labelling fragmentation data together with metastable ion studies in a reverse sector mass spectrometer (from a previous study)] and ab initio reaction coordinate studies at the CCSD(T)/6-31++G(d,p)//B3LYP/6-31++G(d,p) level of theory, have provided the following data concerning the formation of PhO− in the gas-phase from energized systems PhO(CH2)nO− (n = 2–4). All ΔG values were calculated at 298 K. (1) PhO(CH2)2O− effects an ipso Smiles rearrangement (ΔGr = +35 kJ mol−1; barrier to transition state ΔG# = +40 kJ mol−1) equilibrating the two oxygen atoms. The Smiles intermediate reverts to PhO(CH2)2O− which then undergoes an SNi reaction to form PhO− and ethylene oxide (ΔGr = −24 kJ mol−1; ΔG# = +54 kJ mol−1). (2) The formation of PhO− from energized PhO(CH2)3O− is more complex. Some 85% of the PhO− formed originates via a Smiles intermediate (ΔGr = +52 kJ mol−1; ΔG# = +61 kJ mol−1). This species reconverts to PhO(CH2)3O− which then fragments to PhO− by two competing processes, namely, (a) an SNi process yielding PhO− and trimethylene oxide (ΔGr = −27 kJ mol−1; ΔG# = +69 kJ mol−1), and (b) a dissociation process giving PhO−, ethylene and formaldehyde (ΔGr = −65 kJ mol−1; ΔG# = +69 kJ mol−1). The other fifteen percent of PhO− is formed prior to formation of the Smiles intermediate, occurring directly by the SNi and dissociation processes outlined above. The operation of two fragmentation pathways is supported by the presence of a composite metastable ion peak. (3) Energized PhO(CH2)4O− fragments exclusively by an SNi process to form PhO− and tetrahydrofuran (ΔGr = −101 kJ mol−1; ΔG# = +53 kJ mol−1). The Smiles ipso cyclization (ΔGr = +64 kJ mol−1; ΔG# = +74 kJ mol−1) is not detected in this system.Tianfang Wang, Nico M. M. Nibbering and John H. Bowi

Nolanville Comprehensive Plan 2021-2041

Nearly five years after the completion of the 2015 Comprehensive Plan, TxTC partnered with the City of Nolanville again in 2019 with the ENDEAVR project. ENDEAVR (Envisioning the Neo-traditional Development by Embracing the Autonomous Vehicles Realm)— is an ambitious project to re-envision ”smart” city solutions in small towns with students from a wide range of university degree programs in urban planning, landscape architecture, visualization, computer science, and civil, electrical and mechanical engineering. ENDEAVR launched in 2018 with a $300,000 grant from the Keck Foundation, which supports projects that promote inventive educational approaches. The City of Nolanville sought to explore “smart” city solutions to make efficient and prudent improvements to traffic flow, public safety, optimize utility systems, high-bandwidth digital networks, and foster autonomous vehicles. Additionally, TxTC included these “smart” city solutions to update its 2015 comprehensive plan. The new 2020 comprehensive plan embeds “smart” city solutions into its priorities and capital improvement projects to foster diversity and continue to make Nolanville “A Great Place to Live”