The ring puckering potential function of trimethylene sulfide and trimethylene selenide

Four‐Membered Heterocycles: Structure and Reactivity

“…CNDO/2 calculations have been performed to determine the conformation of the parent compound [361]. Experiment values were measured by 1 H NMR in the case of 3,3-dimethylselenetane complexed by palladium(II) halides [362] IR and Raman spectra of this compound have been studied and the different vibrations assigned [363].…”

Modular chemical geometry and symbolic calculation

“…Recent work includes x‐ray crystallography of trimethylene imine, oxetane, and thietane by Esteban et al 30 and in many studies of silaheterocycles by Weidenbruch, e.g., Ref. 31 Nuclear magnetic resonance (NMR) of caryophyllenes by Clericuzlo et al 32 and trimethylene imine in relation to its polymers 33 Electron diffraction of 1,1Me 2 silaCB by Novikov et al 34 Infrared (IR) spectra of 1,1F 2 CB by Lesarri et al 35, oxetane by Moruzzi et al 36, thietane and seletane by Pousa et al 37, and complexes of oxetane and thietane with HCl by Rode and Dobrowolski 38 Raman spectra in Ref. 37 Using the puckering of a cyclobutane ring to drive the synthesis of the tricyclic structure of the naturally occurring guanacastepenes, by Shipe and Sorensen 39 …”

“…Infrared (IR) spectra of 1,1F 2 CB by Lesarri et al 35, oxetane by Moruzzi et al 36, thietane and seletane by Pousa et al 37, and complexes of oxetane and thietane with HCl by Rode and Dobrowolski 38…”

“…These investigators studied the origin of the inversion barrier and obtained the potential energy surface for the puckering vibration. Ab initio methods were used for geometry optimization and, in some cases, to compute potential energy surfaces and barrier heights, in work on CB1,3‐diyls by Abe et al 41 thymine dimers by Aida et al 42 1,3disilaCB and 1,3digermaCB by Avakyan et al 43 Caryophyllenes 32 CB, 1,3‐disilaCB, CBCl and CBBr by Durig and Zhao 44 1Cl‐1silaCB by Favero et al 45 silaCB* + radical cation by Fängström et al 46 CB* + radical cation by Jungwirth et al 28 1,1F 2 CB 35 Thietane and seletane 37 Oxetane and thietane … HCl 38 SilaCB transition state in the reaction of ethylere and silene, by Schaad and Skancke 47 Trimethylene imine 33 Heavily halogenated CBs by Saladino and Tang 48 …”

Unitary Operators and Variational Approaches for One-Dimensional Hamiltonians

“…In order to evaluate the C (N ' n} we employ the "ordered" expansions introduced with Eq. n nl (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) In (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) we have ^/-parameters (/?, h 2 , hz, •••, h N \ which are to be fixed by a minimiza tion procedure. An alternative approach that may be easier to implement would run as follows: evaluate first (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) and minimize this with respect to /?.…”