Volume 50, Issue 12

Deprotonation of the 2-amino- 1,3-dimethylimidazolium salt 5 (obtained through methylation of 2-amino-l-methylimidazole (4)) by KH gives 2-imino-1,3-dimethylimidazoline 6. The trimethylsilylimino compound 14 is formed on the reaction of 6 with chlorotrimethylsilane in the ratio 2:1. Further reaction with chlorotrimethylsilane gives the silylated aminoimidazolium salt 15. The X-ray structures of 5 and 6 are reported.

The reactions of 2-(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2λ 3 -phosphorinan- 4,6-dione (1), 2-bis(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2A3-phosphorinan- 4,6-dione (2), 2-methoxy-1,3,5-trimethyl-1,3,5-triaza-2λ 3 -phosphorinan-4,6-dione (3) and 2-trimethylsiloxy-1,3,5-trimethyl-1,3,5-triaza-2λ 3 -phosphorinan-4,6-dione (5) with hexafluoracetone are described. In the case of 2 and 3 the reaction furnished the spirocyclic compounds 7 and 8. 2-Bis(2-chloroethyl)amino-1,3,5-triphenyl-1,3,5-triaza-2λ 3 -phosphorinan- 4,6-dione (4) did not react. In the case of 1 and 5 rearrangement reactions took place; the (2-chloroethyl)amino substituent of 1 reacted with one of two equivalents of hexafluoroacetone with formation of the spirocyclic phosphorane 6. The reaction of 5 with tetrabromoorthobenzoquinone gave the phosphoryl compound 9. Compounds 6 - 8 were characterized via their 1 H-, 13 C-, 19 F- and 31 P-NMR and mass spectra, compound 9 via its 1 H-, 13 C- and 31 P-NMR and mass spectra. An X-ray crystal structure determination of 8 was conducted; in the six-membered ring the phosphorus atom lies 73 pm out of the plane of the other atoms, and displays trigonal bipyramidal coordination.

Crystals of RbCuSe 4 are orthorhombic, oP24, s.g. P 2 1 2 1 2 1 (No.19), Z = 4 with a = 5.541(2) Å, b = 8.814(2) Å , c = 13.277(9) Å. The crystal structure was determined from diffractometer data and refined to a conventional R of 0.019. RbCuSe 4 is a pseudo-one-dimensional compound, characterized by infinite polyanionic chains 1 ∞ -[CuSe 4 ] - . The atomic arrangement corresponds to that of α-NH 4 CuS 4 .

Single crystals of the so far unknown compounds KCuGd 2 Mo 4 O 16 (I) and KCuTb 2 Mo 4 O 16 (II) have been prepared by flux technique. The compounds crystallize with monoclinic symmetry. space group C 6 2h -C2 /c with (I): a = 5.278(2), b = 12.666(5), c = 19.604(14) Å; β = 92.76(6)°; (II): a = 5.259(13), b = 12.616(3), c = 19.556(9) Å, β = 92.93(4)°, Z = 4. Molybdenum exhibits tetrahedral coordination. The surroundings of copper can be described by distorted tetrahedra, capped by two more distant oxygen atoms, and the rare earth ions show a square antiprism. Potassium is inside an irregular polyhedron. The relationship of the structures of (I) and (II) is discussed with respect to the KLnMo 2 O 8 type compounds. Coulomb term calculations of the lattice energy indicate an oxidation state of copper higher than Cu I .

The arylxenonium cation in the salt [C 6 F 5 Xe]+ [AsF 6 ] - is isoelectronic to C 6 F 5 I, but coordinatively unsaturated with respect to N-bases like MeCN and pyridines. Co-ordination of strongly basic pyridines causes weakening of the Xe-C bond and C 6 F 1 radical formation. The thermal decomposition of pyridine co-ordinated arylxenonium cations gives three groups of products: C-pentafluorophenylated pyridines, N-pentafluorophenylated pyridinium and N-protonated pyridinium salts. The co-ordination ability of the different pyridines shows a good correlation (C 6 F 5 group) with the 19 F NMR shift values of the p-F atom and the coupling constants 3 J ( 19 F- 129 Xe). An X-ray structure analysis was performed for the co-ordination product [C 6 F 5 Xe · 2,6-C 5 H 3 F 2 N ]+ [AsF 6 ] - and for [C 6 F 5 -C 5 H 5 N] + [(C 6 F 5)2 BF 2 ]-, which was obtained by thermolysis of the corresponding adduct.

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), n Pr (c), n Bu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ 2 -diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ 2 -diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = t Bu (1e). The products were characterized by multinuclear magnetic resonance ( 1 H, 13 C, 15 N, 29 Si, 119 Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].

In the reaction of N-methylaminomethylene-dimethylphosphine oxide and sulfide with diethylaminotrimethylsilane, N-methyl-N-trimethylsilyl-aminomethylene-dimethylphosphine oxide (1) and sulfide (2) were formed. These compounds were allowed to react with a series of P(III)C1 compounds to give the corresponding methylaminomethylene-bridged diphosphorus compounds (3 - 10) with phosphorus in the combination λ 4 P(V)/λ 3 P(III). In the oxidation of some of these compounds by the hydrogen peroxide-urea 1:1-adduct (NH 2 ) 2 CO ·H 2 O 2 or sulfur, the corresponding λ 4 P-CH 2 -N(Me)-λ 4 P-derivatives (11 - 16) were formed. Different reaction behaviour was observed depending on the substituent at λ 4 P or on the oxidizing agent. Reaction of 1 with trimethylsilylmethyl tetrafiuorophosphorane and with bromotriphenylphosphonium bromide furnished, besides trimethylhalosilane, the corresponding diphosphorus compounds (17 ) and (18) with phosphorus in the combination λ 4 P(V)/λ 5 P(V) (17) and λ 4 P(V)/λ 4 P(V) + (18). Oxidation of N-diphenylphosphino-N-methyl-aminomethylene-dimethylphosphine oxide (3) by tetrachloro-o-benzoquinone led to the corresponding addition product in impure form. Reaction of 3 with hexafluoroacetone (HFA) yielded a mixture of two products which could not be separated. Both oxidation (>N-PPh 2 → >N-P(:O)Ph 2 ) and insertion of HFA into the P-N-bond (>N-PPh 2 → >NC(CF 3 ) 2 -O-PPh 2 ) occurred. In the reaction of 1 with methyldichlorophosphine, both the mono- and disubstituted products, 22 and 23, were formed, independently of the reaction conditions and molar ratio of the starting compounds. The reaction of 1 with bis(diethylamino)chlorophosphine was unusual. Upon separation of both trimethylchlorosilane and dimethylaminotrimethylsilane, compounds 24 - 26 were formed, with the central phosphorus atom bearing one, two or three methylaminomethylene-dimethylphosphine oxide groups, respectively. Simultaneously, tris(diethylamino)phosphine was formed.

The reactions o f 2-hydro-1,3,5-trim ethyl-1,3,5-triaza-2-oxo-2λ 4 -phosphorinan-4,6-dione 1 with the triazine derivatives, 1,3,5-trimethyl- and 1,3,5-tribenzyl-hexahydro-1,3,5-triazine, are described. The reaction of three equivalents of 1 with one equivalent of the triazine derivative gave 2 and 3. Both compounds were characterized via their 1 H, 13 C, and 31 P NMR spectra, mass spectra and, in the case of 2, by an X-ray crystal structure analysis, which showed an almost planar six-membered ring; hydrogen bonds of the form N-H···O link the molecules in centrosymmetric pairs. The reactions of 1 with the aldehydes glyoxylic acid, 2-hydroxybenzaldehyde and 3,4,5-trimethoxybenzaldehyde gave addition products. The C (:O) group o f the aldehyde is inserted into the P -H bond o f 1. The resulting compounds 4 ,5 and 6 were characterized through their 1 H, 13 C, and 31 P NMR spectra, and mass spectra.

Cationic η 2 -thiocarbene complexes of molybdenum and tungsten [Cp(CO) 2 Me][ BF 4 ] (M = Mo, W; R = Ph, Tol; L = CO, PMe 3 ) react with the germylene Ge{N( t Bu)CH 2 CH 2 N( t Bu)}, the plumbylene Pb{N(SiMe 3 ) 2 } 2 , or with sodium azide and sodium thiosulfate to give neutral metalla-thia-cyclopropane complexes Cp(CO) 2 -. Instead of the expected cycloaddition or substitution reactions the formal addition of thiomethanolat at the carbene carbon atom is observed. On treating the corresponding trimethylphosphine substituted η 2 -thiocarbene complex of molybdenum [Cp(CO)(PMe 3 )[BF 4 ] with diethylamine or N,N,N′,N′-tetramethylguanidine a cationic molybda-thia-cyclopropane system is formed. The products have been characterized by 1 H, 13 C, 31 P NMR, IR and mass spectra. The crystal structure of 5a has been determined; space group with a = 1340,4(2), b - 1097,7(1), c = 1101,8(5) pm and Z = 4.

The influence of H 2 O 2 on the UV degradation of the broadly used aminopolycarboxylates EDTA and NTA in aqueous solution was investigated. The photochemical degradation in the UV /H 2 O 2 process was compared with classical oxidative treatment of potable water. The German drinking water regulation (Trinkwasserverordnung) was the orientation for all experiments. The Advanced Oxidation Process (AOP) turned out to be superior to the classical oxidation processes. The photochemical degradation of EDTA and NTA by UV irradiation could be significantly stimulated in the presence of H 2 O 2 . There was a strong increase in the degradation rate and a decrease in the quantum yield of the aminopolycarboxylates. Experiments with butyl chloride as radical scavenger proved the photolytically generated hydroxyl radicals to be responsible for the increase in the degradation rates. The effect of increasing the degradation rate at higher concentrations of H 2 O 2 was limited, because the steady-state concentrations of the hydroxyl radicals as reactive species, did not increase at the same rate as the initial concentration of H 2 O 2. Low amounts of iron dissolved from the high-grade steel photoreactor walls had a significant catalytic effect on the degradation.

The compound Cu 2 Zn(B 2 O 5 )O was prepared by using a B 2 O 3 flux technique, and single crystals were investigated by X-ray diffraction (monoclinic symmetry, space group C 5 2h -P2 1 /c ). The structure is isotypic to Cu 2 Co(B 2 O 5 )O with lattice parameters a = 327.38(2), b = 1479.4(3), c = 915.39(13), β = 95.794(11)°, Z = 4, but with the significant difference that zinc is pentacoordinated by oxygen. Copper exhibits a nearly square planar or a square pyramidal coordination, respectively. The structure contains isolated B 2 O 5 units and oxygen which is not coordinated to boron.

Mannich bases were prepared from substituted phenols with aliphatic amines and formaldehyde. Amine exchange with N-methyl-2-naphthylamine followed by a Hofmann Martius rearrangement gave rise to o,o′-amino-hydroxy-diphenylmethane derivatives. Under cyclization conditions some of these compounds produced spirocyclohexadienones, which are the ipso analogs to the hypothetic intermediates postulated in the aminomethylation mechanism of phenols.

From forty one chiral benzodiazepin-2-ones the UV and CD data are reported and the bands discussed with respect to corresponding electronic transitions respectively stereochemical features.