Volume 35, Issue 9

In the reaction of CH 3 SO 2 F with hydroxylamine the products CH 3 SO 2 N(H)OH, H 3 NOH + CH 3 SO 3- , and H 5 N 2 +CH 3 SO 3- are formed. H 2 NO-Si(CH 3 ) 3 reacts with CH 3 SO 2 F to yield mainly H 5 N 2 + CH 3 SO 3_ . These results are explained by consecutive reactions of the intermediate CH 3 SO 2 ONH 2 .

The vibrational spectra of the cage compounds P4S3, P4Se3 and AS4S3 have been recorded in the solid and the molten state. The vibrational spectra of crystalline As4Se3, which decomposes during melting, have been investigated. The frequencies wore assigned using the concept of group frequencies. A new assignment of the Raman frequencies is proposed for P 4 S 3 based on new po­larization data. The frequencies of the arsenic compounds are reported for the first time. The Raman spectra of the molten compounds suggest that the cage structure is retained in the molten state.

The complex AsPh 4 [MoN(N 3 ) 4 ] is prepared by the reaction of AsPh 4 [MoNCl 4 ] with silver azide in dichloromethane suspension in the presence of dry sodium sulfate. The IR spectrum indicates an Mo≡N group and four covalently bonded N 3 groups for the [MoN(N 3 ) 4 ] ⊖ anion. AsPh 4 [MoN(N 3 ) 4 ] crystallizes in the triclinic space group P1̄ with two formula units in the unit cell. The crystal structure was solved by X-ray diffraction methods (R = 0,038; 4049 independent reflexions). The structure consists of AsPh 4 ⊕ cations and [MoN(N 3 ) 4 ] ⊖ anions. The short MoN bond length of the nitrido ligand (163 pm) corresponds to an Mo ≡ N triple bond. The steric effects of the lone pairs of the α-N atoms of the azido groups with tho MoN ligand cause a propellerlike twisted conformation of the four azido groups.

With R 2 PSi(CH 3 ) 3 (R = C 6 H 5 , i-C 3 H 7 , t-C 4 H 9 ) one Cl atom of 3,4-dichlor-5-methoxy-2(5 H)-furanon (1) is substituted by the R 2 P group. An x-ray crystal structure analysis of the phosphino derivative with R = C 6 H 5 (2) it has shown that of the two Cl atoms in 1 only the β-position (to C= O) is substituted. The coordination chemistry of 2 and its bis- (diphenylphosphino) derivative (3) is studied by preparation of the compounds 2 · Mo(CO) 5 and 3 · Mo(CO) 4. With PdCl 2 · 2 C 6 H 5 CN (2) gives a dinuclear complex [2 · PdCl 2 ] 2 , with bridging Cl atoms. The structure is established by a comparison with the similar complex of PdCl 2 and 2-chloro-diphenylphosphino-maleic acid dimethylestor, which was synthe­sized as a model compound and studied by x-ray crystal structure analysis.

The reaction between C 5 H 5 Re(CO) 3 and LiSi(C 6 H 5 ) 3 affords the compound C 5 H 5 (CO) 2 ReC(OCH 3 )Si(C 6 H 5 ) 3 after subsequent alkylation with CH 3 SO 3 F. This complex reacts with BF 3 to yield [C 5 H 5 (CO) 2 ReCSi(C 6 H 5 ) 3 ]BF 4. This cationic carbyne complex yields C 5 H 5 (CO) 2 ReC(CH 1 )Si(C 6 H 5 ) 3 with LiCH 3 and C 5 H 5 (CO) 2 ReC(H)Si(C 6 H 5 ) 3 with (C 4 H 9 ) 4 NBH 4 . Reaction conditions, properties and spectroscopic data of the new com­pounds as well as an X-ray structure determination of C 5 H 5 (CO) 2 ReC(H)Si(C 6 H 5 ) 3 are reported.

The stability of (SiF 3 ) 2 O and the chemical behaviour with HF and CsF has been described. The reactivity of hexafluorodisiloxane with various strongly oxidizing fluorides (XeF 6 , XeF 4 , XeF 2 , KrF 2 , IF 7 , BrF 5 , ClF 5 , ClF 3 , ClF, UF 6 ) and oxide fluorides (XeOF 4 , ClO 2 F) was investigated, particularly with respect to the preparation of oxide fluorides such XeF 6 + (SiF 3 ) 2 O → XeOF 4 + 2 SiF 4 (I) in comparison to hydrolysis reactions with H 2 O or SiO 2 /HF. In summary, all the studied compound react more slowly with (SiF 3 ) 2 O than with H 2 O. The reaction (1) can be recommended as a safe procedure to prepare XeOF 4 . By heating a mixture of UF 6 and (SiF 3 ) 2 O uranium oxide fluorides are obtained. With β-UV irradiation was observed. It is remarkable that many of the investigated fluorides and fluorine oxidize the (SiF 3 ) 2 O to oxygen. (SiFa 3 ) 2 O shows no reaction with HF. IF 7 catalyzes only the decomposition of (SiF 3 ) 2 O.

Acidity constants of ammine complexes of tetravalent platinum in aqueous solutions have been determined by a spectrophotometric method at very low ionic strengths and extrapolated to zero ionic strength. Temperature variations of pK-values (25 °C and 50 °C) yield thermodynamic parameters for two successive deprotonation steps of hexaammineplatinum(IV), pentaamminechloroplatinum(IV), and tris(ethylenediamine)pla- tinum(IV) complexes and for the deprotonation of pentaammineaquacobalt(III) ion. The enthalpy changes for the first and second steps are similar and range from 50 to 75 kJ/mole while for the aqua ligand of Co(III) 33 kJ/mole are found. The very large dif­ference in the entropy changes (about 70 to 80 J/K mole for the first step and -10 to + 20 J/K mole for the second step) is interpreted by a model of solvation change. The primary hydration sphere of strongly oriented and immobilized water dipoles around the highly charged complex cation is transformed to a hydrogen-bonded solvation sheath when the electric field of the complex is weakened upon release of the first proton.

The preparation of the six-membered rhenacyclohexanes (1a, b) [R = CH 3 (a), C 6 H 5 (b)] is accomplished by heterolytic cleavage of the Re-Re bond in the binuclear anions [(OC) 4 ReP(R 2 )O] 2 2- with strong electrophiles like the alkanediylbis(triflate) (CH 3 ) 2 C(CH 2 Y) 2 (Y = OSO 2 CF 3 ). followed by an attack of the co-positioned carbenium-like C atom on the phosphinite oxygejn of the anion. 1 a, b insert SO 2 under ring expansion yielding the seven-memberod heterocyeles (2a, b). 1b crystallizes triclinic in the space group P1̄ with Z = 2. Some characteristic IR and NMR data are discussed.

Dichloro(phthalocyaninato)silicon(IV) (1) reacts with various bis-bromomagnesium- alkynes to form the corresponding poly-trans(alkynyl)phthalocyaninat osilicon(IV) compounds (5), (11) and (18). The electrical conductivity of 5, 11 and 13 was measured with and without doping.

The chloro-tris(carbonylmetalato)tin(IV) compounds, listed in Table I, are obtained by the reaction of TlCo(CO) 4 or Tl[Mn(CO) 5 ] 3 with the dichloro(carbonylmetalato)tin(IV) complexes Cl 2 Sn[M(CO) 5 ] 2 (M = Mn, Re), Cl 2 Sn[Fe(CO) 2 Cp] 2 , Cl 2 Sn[Cr(CO) 3 Cp][Mn(CO) 5 ] and Cl 2 Sn[Cr(CO) 3 Cp][Fe(CO) 2 Cp] in the molar ratio 1:1. Chloro-tris(carbonylmetalato)- tin(TV) compounds of the same type are also formed by treatment of TlCo(CO) 4 with the trichloro(carbonylmetalato)tin(IV) complexes in the molar ratio 2 : 1. The new compounds are characterized by their analyses, mass, IR and FIR spectra. The X-ray analysis of ClSn[Fe(CO) 2 Cp] 2 [Co(CO) 4 ] (space group P2 1 /c) confirms the presence of 3 carbonyl - metalato groups attached to tin.

PF 5 reacts with Mo 3 Si(Bu t )NPF 2 (E) (E = lone electron pair or OC(CF 3 ) 2 C(CF 3 ) 2 O) to give products whose formation can be rationalised in terms of assuming the decomposition of the intermediates F 4 PN(Bu t )PF 2 (E) into Bu t F and F 3 P = N-PF 2 (E). Bu t F, in the presence of PF 5 , trimerises to give a 1 : 1 mixture of tri-iso-butene isomers. During this reaction HF is formed, giving rise to additional Si-N and P-N bond cleavage reactions in which the compounds Bu t NHPF 2 , F 3 P(E), Bu t NH 3 + PF 6- and NH 4 +PF 6- are formed.

Eight-membered rings of the composition [SO 2 (NR) 2 PR′] 2 3a-d with R = CH 3 , C 2 H 5 , and R′ = CH 3 , C 6 H 5 , were prepared from substituted sulfamides and dichlorophosphanes in the presence of a tertiary amine. These molecules were characterized on the basis of 1 H and 31 P NMR investigations and of mass spectra. 3 a reacts with phosphorus pentachloride to yield the spirocyclic derivative 4 with the phosphorus atom in the center of two four-membered rings. Methyliodide reacts with 3 a and 3 b under opening of the eight- membered ring and formation of phosphonium salts. The structure of 3 b is discussed in detail. 8b crystallizes in the orthorhombic space group Pna 2 1 with a = 12.60(0), b = 13.27(1), c = 12.62(4) Å.

As it proved impossible, to compute a unique and meaningful General Valence Force Field for SF4 from the known experimental data, this was realized by an ab initio cal­culation using a basis set of 3-3-21 + 1 d G functions for the S-, and 4-21 G functions for the F-atom. The values of the stretching force constants are f (S-F eq ): 5.36 mdyn/Å, f(S-F ax ): 3.25 mdyn/Å. Problems of assignment of the deformational modes could be settled conclusively.

ClONO 2 can be prepared in good yields from the reactions of anhydrous metal nitrates M(NO 3 ) 2 (M = Ca, Sr, Pb) with ClF as well as from the direct reaction of Cl 2 , HgO and N 2 O 5 .

The reaction of MoCl 4 (bipy) with an excess of (CH 3 ) 3 SiN 3 in 1,2-dichloroethane results in the formation of a mixture of MoN(N 3 ) 3 (bipy) and Mo(N 2 )Cl 2 (bipy). The latter is an insoluble, brownish compound of yet unknown structure. MoN(N 3 ) 3 (bipy) is very soluble in 1,2-dichloroethane and easily hydrolysed. It can be crystallized from toluene in the form of explosive, red crystals of the space group P 2 1 /n. The crystal structure is built up by monomeric complexes, in which the Mo atom has a distorted sixfold coordination. The three azido groups are located cis to the nitrido ligand, with their free electron pair at the α-N-atom pointing away from the closely neighbouring nitrido ligand. The bipyridine forms two bonds of quite different length (224,0 and 241,9 pm) with the Mo atom, as trans to the triply bounded nitrido ligand (Mo≡N = 164,2 pm) only a weak interaction is possible.

The acylphospholes which are available from dibenzophosphole and the anhydrides [RC(O)] 2 O react in ether with rigorously dried molecular oxygen to the (trifluoro)acetylphosphole oxides (2a, b), which are extremely sensitive towards nucleophiles. With stoichiometric amounts of water the P-C bond in 2a, b is cleaved hydrolytically. As a result of this hydrolysis in several reaction steps one obtains the phosphorylated alcohols (3a, b). Particularly in solution 3b is transformed quickly into the thermodynamic more stable phosphinate (4b). The chemical and spectroscopical pro­perties of the acylphospholes 1a, b and their derivatives are compared with the correspon­ding already known acyl(diaryl)phosphanes.

Triaminofluorosilanes with bulky amino groups are prepared by the reaction of bis- (organyl-trimethylsilyl)amino-difluorosilanes with lithiated amines. A 1,3-migration of trimethylsilyl groups from bulky alkylamino substituents to arylamino substituents is observed in these reactions. Structural isomers of the new triaminofluorosilanes were isolated. The silyl group migration depends on steric and electronic effects. Further reactions of the triaminofluorosilanes with butyllithium and trifluoroorganylsilanes lead to the formation of difluorosilyl-substituted triaminofluorosilanes and LiF. The symmetric compounds show AB-systems for the fluorine atoms of the difluorosilyl groups in the low temperature 19 F NMR Spectra, due to hindered rotation about the Si-N-bond. The coalescence temperature depends on the bulkiness of the substituents and is observed at or about room temperature.

X-ray investigations of a great number of samples along the specifically chosen tie-lines in the isothermal sections of the system U-Cu-Al (800 °C) indicated the existence of two new ordered ternary phases, i.e. U 2 Cu 3 Al and UCuAl 2 . The first one is hexagonal (S. G. P6 3 /mmc, MgZn 2 -type), with a = 5.065 ± 0.005 Å, c = 8.307 ± 0.005 Å and c/a = 1.640. The ordered atomic arrangement of all atoms, as confirmed by trial and error method is consistent with a rather uncommon superstructure of the MgZn 2 -type. UCuAl 2 is tetragonal, a = 3.857 ± 0.005 A, c = 8.736 ± 0.005 A, c/a = 2.265, probable space group is I4/mmm, and represents an ordered ternary structure variant of the TiAl 3 type. The crystal structures of these two new phases were correlated, in terms of stacking sequences, with those which were identified in this system previously.

Experimental and computational evidence indicates that the five-membered ring system S 3 N 2 + has an 2 A 2 ground state. Different possibilities for the stabilization of S 3 N 2 + are discussed on the basis of MO arguments and calculations using semiempirical and ab initio (STO 3G) methods. The theory allows the rationalization of the structures of S 3 N 2 Cl 2 , S 3 N 2 X and [S 6 N 4 ] 2+ . The bonding between the two S 3 N 2 + moieties in [S 6 N 4 ] 2+ is described as an electron rich six electron four center bond.

A peptide, apparently new, has been isolated from the anterior lobes of bovine pituitary glands by the following steps: (1) lyophilization of frozen tissue; (2) homogenization; (3) extraction with an aqueous buffer; (4) gel filtration; (5) anion and then (6) cation exchange chromatography; (7) HPLC. One antioxidant and two proteolytic inhibitors were present during buffer extraction to avoid artifactual reactions. Amino acid analyses consistently revealed the same amino acids and no others on different specimens, one year apart. The composition was estimated as: 4 Asp, 2 Thr, 5 Ser, 8 Glu(x), 5 Pro, 10 Gly, 4 Ala, 2 Val, 2 Met, 1 Ile, 2 Leu, 1 Tyr, 1 Phe, 2 His, 3 Lys, 2 Arg (5600 daltons). Cysteine and tryptophan were absent. An approximate molecular weight by gel filtration was 7200 daltons. The isoelectric point was 6.1. The peptide showed a dose-response activity in the range of 0.001-1.0 μg in a rabbit adipose system, in vitro. The peptide is tentatively designated as adipotropin, because it has no unequivocal chemical relation­ship to other relevant lipolytic peptides, and because it has the highest molar potency, in vitro, of these peptides, including pACTH.