Colorless Crystalline Solids Research Articles

Discovery, characterisation, and utilisation of selenoxide-sulfonic acid salts: A new class of selenoxide-based oxidant and stable selenoxide equivalent.

The preparation and characterisation of a novel class of salts of selenoxides with sulfonic acids are described. They are readily prepared by simple addition of the sulfonic acid to a solution of selenoxide, and removal of solvent. In most cases they are colourless crystalline solids and are considerably more stable than the parent selenoxides, allowing full characterisation and X-ray crystallographic analysis. They also efficiently oxidise sulfides to sulfoxides, with no overoxidation, and clean regeneration of selenide. Their structure has been confirmed by 1H NMR spectroscopy and X-ray crystallography.

Stability constants of the zinc(II), cadmium(II) and mercury(II) complexes of the mono-aza coronands 1,4,7,10-tetraoxa-13- azacyclopentadecane (L 1), 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (L 2) and 1,4,7-trioxa-10-azacyclododecane (L 3). Crystal and molecular structures of the cadmium complexes of L 1 and L 2

The stability constants for the 1:1 complexes of zinc, cadmium and mercury with 1,4,7,10-tetraoxa-13-azacyclo- pentadecane (L 1), 1,4,7,10,13-pentaoxa-16-azacyclooctadecane (L 2) and 1,4,7-trioxa-10-azacyclododecane (L 3) have been determined potentiometrically (0.1 M NEt 4ClO 4, 95% methanol). Reaction between L 1 or L 2 and cadmium nitrate tetrahydrate in methanol results in the isolation of colourless crystalline solids. Crystals of [Cd(L 1)(NO 3) 2] are monoclinic, space group P2 1/ c with a=7.614(2), b=28.566(2), c=7.707(1) Å, β=107.364(9) o; R=0.025, R w=0.027 for 2195 ( I> 3σ( I)) reflections. The structure of [Cd(L 1)(NO 3) 2] consists of an almost planar macrocyclic ligand enclosing a cadmium ion in its cavity, with a monodentate and a bidentate nitrate ligand coordinating the cadmium ion on opposite sides of the macrocycle. Crystals of [Cd(L 2)(NO 3) 2] are orthorhombic, space group Pca2 1 with a=8.738(11), b=14.140(9), c=15.176(8) Å; R=0.019, R w=0.022 for 3058 ( I> 2.5σ( I)) reflections. The structure of [Cd(L 2)(NO 3) 2] consists of a cadmium atom enclosed in the cavity of the macrocycle, with a monodentate and a bidentate nitrate ligand on opposite sides of the macrocycle. Two of the oxygen atoms of L 2 in [Cd(L 2)(NO 3) 2] do not coordinate the cadmium ion, but the remaining donor atoms of the macrocycle form an almost planar assembly around the cadmium.

Novel ammonium hexafluoroarsenate salts from reaction of (CF 3) 2NH, CF 3N(OCF 3)H, CF 3N[OCF(CF 3) 2]H, CF 3NHF and SF 5NHF with the strong acid HF/ASF 5.

Reactions of the fluorinated amines (CF 3) 2NH, CF 3N(OCF 3)H, CF 3N[OCF(CF 3) 2]H, CF 3NHF and SF 5NHF with the strong acid HF/AsF 5 form the corresponding ammonium salts R f 1R f 2NH 2 +AsF 6 − and R fNFH 2 + AsF 6 − in high yield. [R f 1=CF 3, R f 2=CF 3, CF 3O, (CF 3) 2CFO; R f=CF 3, SF 5] The colorless crystalline solids are stable for prolonged periods at 22°C in sealed FEP containers. They have dissociation pressures at 22°C ranging from ∼5 torr (R fNFH 2 + AsF 6 −) to ∼50 torr [CF 3N(OCF 3)H 2 +AsF 6 −]. 19F NMR and Raman spectroscopy were used to identify the compounds.

Oxy- and thio-phosphorus acid derivatives of tin: XIII. Di- and triorganotin(IV) monothiophosphate esters

Eleven di- and triorganotin(IV) O,O′-diorganomonothiophosphate esters, RnSn[OP(S)(OR′)2]4-n where n = 2, R = CH3, C2H5, n-C4H9, n-C8H17, C6H5 and R′ = CH3 and where R = C6H5 and R′ = C6H5 and where n = 3, R = CH3, n-C4H9, C6H5 and R′ = CH3 and where R = C6H5, C6H5CH2 and R′ = C6H5, are synthesized in high yield by the reaction of the corresponding organotin(IV) chlorides with the sodium salt of the R′ = CH3 acid and the triethylammonium salt of the R′ = CH3 acid and the triethylammonium salt of the R′ = C6H5 acid in ethanol. The products are colorless crystalline solids or oils, soluble in organic solvents. Vibrational spectroscopic band assignments can be made for the ν(P-O) (1220-1050 cm−1), ν(P-OR) (1000-900 cm−1), ν(P=S) (700-600 cm−1), ν(Sn-C) (600-500 cm−1), and ν(Sn-O) (500-400 cm−1).The tin-119m Mössbauer isomer shift (IS) values confirm tin as tin(IV), but the quadrupole splitting (QS) values fall into two groups with the tribenzyl- and di-n-octyltin derivatives exhibiting small magnitudes typical of four-coordination, with unidentate ligands. The other diorganotins exhibit very large QS values, corresponding to six-coordination with trans-R2Sn groups. From a point-charge model calculation, the dimethyltin group is linear, and the diphenyltin angles are 173.2 and 139.4° for (C6H5)2Sn[OP(S)(OR)2]2 where R = CH3 and C6H5, respectively. However, the observation of both νasym and νsym (Sn-C) in both the infrared and Raman spectra of the dimethyltin derivative rules out a strictly linear array. The strong Mössbauer spectra exhibited by the R2Sn[OP(S)(OCH3)2]2 derivatives at room temperature where R = CH3 and C2H5 suggest intermolecular association, and variable-temperature data for the R = C6H5 derivative yield a slope of dln A/dT = −0.972 × 10−2 K−1, reflecting a tightly-bound lattice as well, probably containing bridging ligands. No fragments of mass greater than the parent ion or containing more than one tin atom are seen in the mass spectra of any of the compounds studied, however. The triorganotins, other than the tribenzyl-derivative, exhibit large QS values signifying five-coordination, and the NMR |2J(119Sn-C-1H)| of 74.0 Hz for the trimethyltin derivative in solution is corroboratory. However, the negative tin-119 NMR chemical shift relative to tetramethyltin for the tri-n-butyltin derivative corresponds to four-coordination in solution. Bis(O,O′-diphenylthiophosphato)diphenyltin(IV) hydrolyzes on the benchtop or in wet ether to give the intermediate, dimeric hydrolysis product, [(C6H5)2SnOP(S)(OC6H5)2OH]2.

Derivatives of cis-NPCl2 (NSOCl)2 and (NPCl2)2NSOCl, VI Pyridinium Derivatives of cis-NPCl2(NSOF)2 and cis-NPCl2(NSOCl)2

The compounds with composition NPCl(NSOF)2(C5H5N)OH (1) and NPCl(NSOCl)2 (C5H5N)OH (2) are prepared by reaction of cis-NPCl2(NSOX)2 (X = F, Cl) with pyridine in ether. The pyridinium derivatives are colourless crystalline solids. Tentative structure assignments are given based on NMR data.