Boron and gallium esters derived from 2-(1,3,5-dithiazinan-5-yl)-ethanols

Abstract

Compounds 2-(1,3,5-dithiazinan-5-yl)ethanol (1), 2-methyl-2-(1,3,5-dithiazinan-5-yl)ethanol (2) and 2-phenyl-2-(1,3,5-dithiazinan-5-yl)ethanol (3) reacted with BF 3 ⋅OEt 2 and BCl 3 ⋅DMS, 1 and 2 with (Ph 2 B)O, and 2 and 3 with GaCl 3 giving the corresponding chelates, bearing N→BF 2 O, N→BCl 2 O N→BPh 2 O, and N→GaCl 2 O groups. The internal coordination N→M (M = B or Ga) afforded spiro-compounds, where nitrogen is the central atom. Compounds were mainly characterized by 11 B, 1 H and 13 C NMR. The N→B or N→Ga coordination bond was detected in the 1 H spectra because coordination stops the ring inversion of the dithiazinane ring differentiating equatorial and axial protons. The presence of a sterogenic center at the ethanol arm (ligands 2 and 3), differentiates C4H 2 and C6H 2 upon coordination. Minimum energy structures for boron compounds were calculated [ab initio 6-31G(d,p)]. VT NMR experiments for diphenyl borinic esters were performed in order to estimate the N→BPh 2 coordination energy. X-ray diffraction analyses of the hydrochloride of ligand 1 and of the gallium compound prepared from 2 were obtained.

An orthorhombic polymorph of 2-(1,3,5-dithiazinan-5-yl)ethanol or MEA-dithiazine

“…The nitrogen atom is sp 3 hybridized, as expected for a tris(methylene) substituted amine [C-N-C angles range from 113.16 (5) to 114.49 (5) , the bond angle sum is 342.06 ], the dithiazine ring exhibits the expected chair conformation, and the ethanolamine unit is substituted onto the ring in an axial orientation. The title compound has this in common with the other structures featuring a MEA-dithiazine moiety: The previously reported polymorph (form I) in space group I4 1 /a and also the bromide and chloride salts of MEA-dithiazine, which are protonated at the amine and isomorphous (Bushmarinov et al, 2009;Galvez-Ruiz et al, 2008), also feature an sp 3 -hybridized amine N atom, as well as a chair conformation dithiazine ring axially substituted by the ethanolamine.…”

“…10) graph-set motif. Three crystalline organic salts of 2-(1,3,5-dithiazinan-5-yl)ethanol have also been reported, including one with bromide and two with chloride counter-ions (HOSKIK and HOSKOQ; Bushmarinov et al, 2009;HOSKOQ01;Galvez-Ruiz et al, 2008). All three salts are isostructural, possessing a protonated nitrogen atom and charge-assisted O-HÁ Á ÁBr/Cl and charge-assisted N-HÁ Á ÁBr/Cl hydrogen bonds and R 2 4 (14) graph sets.…”

Plio-Quaternary extensional tectonics of the Central Anatolian Plateau: a case study from the Tuz Gölü Basin, Turkey

“…11,34 Therefore, for compound 5, the intramolecular N→ B coordinated system should be present according to these data. 35,36 In substituted metallo and metal-free phthalocyanines, strong absorption is detected in the visible region between 650 and 690 nm, termed the Q band, and in UV between 320 and 370, called the Soret band. 37 The Soret band arises from the deeper π -levels/LUMO transition and the Q band is attributed to the π − π * transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) of the phthalocyanine ring.…”