摘要:

AbstractThe dependencies of Kα line shifts of the P and S atoms on effective charges of the atoms, calculated by CNDO/S, CNDO/2, INDO, and MNDO methods in the minimal and extended basis sets, have been investigated for model compounds. Good linear relationships between Kα shifts and atomic charges have been obtained for all cases investigated except for CNDO/2 and INDO calculations in the extended basis set. It is found that the PS bond ionicity is a nearly constant value, whereas the PS bond ionicity increases linearly with an increase in the positive charge of the central P atom. It is shown that the P and S atom charge in sulfides and phosphines containing no substituents with a strong M‐effect at the central atom depend only on inductive substituent effects. Also, the positive charge on the central atom increases with the growth of the π‐donor properties of substituents in sulfides and phosphines containing substituents exerting a strong M‐effect, as well as in phosphoryl and thiophosphoryl compounds

ISSN:1042-7163    

DOI:10.1002/hc.520030402

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractRoom temperature reactions of S4N4with (amino) diphenylphosphines, (R)Ph2P, have basically yielded two different types of SN heterocycles under two different stoichiometric conditions. Phosphiniminocyclotrithiatriazenes, (R)Ph2PNS3N3(R = C4H8N, C5H10N, C6H12N, CH3NC4H8N, (C6H11)2N, and (C6H5CH2)2N) have been obtained (yield 45–76%) from a 1:2 mole ratio (S4N4:(R)Ph2P) reaction, while the disubstituted S4N4derivatives, 1,5‐[Ph2(R)PN]2S4N4(R = C4N8N, C5H10N, and C6H12N) have been obtained (yield 30–45%) only from a 1:3.5–4 mole ratio reaction. All the 1,5‐[Ph2(R)PN]2S4N4derivatives prepared in this study undergo a room temperature solution phase transformation to the correspo

ISSN:1042-7163    

DOI:10.1002/hc.520030403

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractCondensation of SiO with sodium or potassium, respectively, leads to the formation of Na+(SiO)−and K+(SiO)−. The SiO force constant is reduced to 6.15 mdyn/Å and 6.30 mdyn/Å with respect to uncoordinated SiO (f = 9.0 mdyn/Å). From these results a similar type of bonding can be concluded for the charge transfer complexes Ag+(SiO)−and Ag+(SiS)−publishe

ISSN:1042-7163    

DOI:10.1002/hc.520030404

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractCo‐condensation of silver atoms and SiS in an argon matrix leads to the formation of Ag(SiS). The IR spectrum can be interpreted in two different ways: Isotopic shifts (28Si/29Si,28Si/30Si,32S/34S) imply a side‐on coordination of SiS to silver. On the other hand, the SiS frequency and the isotopic shifts can be assigned to an isolated SiS−molecule. The SiS force constant is reduced from 5.0 mdyn/Å in free SiS to 3.9 mdyn/Å in AgSiS. Ab initio investigations confirm the formation of an ion pair Ag+(SiS)−, admitting some electron del

ISSN:1042-7163    

DOI:10.1002/hc.520030405

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractDiisopropyl 1,1‐dichloroalkylphosphonates bearing various groups (alkyl, aryl, allyl, benzyl, phenylthiolate, trimethylsilyl) in the α‐position were reduced to the corresponding primary 1,1‐dichlorophosphines by the LiAlH4‐AlCl3system in diethyl ether. Subsequent dehydrochlorination with tertiary amines in the presence of trapping dipolar compounds (ethyl diazoacetate or n‐hexylazide) led to the expected 1,2,4‐diazaphospholes or 3H‐1,2,3,4‐

ISSN:1042-7163    

DOI:10.1002/hc.520030406

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

Abstract4‐Bromodiazaphosphole‐3‐oxides or sulfides can be obtained by reaction of the corresponding unsubstituted derivative with appropriate reagents. PTAB was demonstrated to be very regio‐ and stereoselective, allowing bromination exclusively at the 4‐position of the ring with prevalent or exclusive formation of one of the two possible isomers. However, when regioselectivity is not required, cheaper and more available bromine or NBS can be used conveniently. 4‐Chlorodiazaphosphole‐3‐oxides can be obtained by reaction of the corresponding unsubstituted derivative with NCS. 4‐Bromodiazaphosphole‐3‐oxides undergo stereoselective methanolysis as well as parent

ISSN:1042-7163    

DOI:10.1002/hc.520030407

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe title compounds3and7are novel heterocyclic systems incorporating two‐coordinate phosphorus. They are obtained in reasonable to good yields from the condensation of suitable 2‐ethyl‐3‐alkylthiazolinium and ‐benzothiazolium bromides2and6with phosphorus trichloride in the presence of triethylamine in an aprotic solvent. Intermediate dichlorophosphino‐substituted N‐ylides can be observed or isolated in some cases. From a 2‐methyl‐3‐alkylthiazolinium bromide (2a), a 1‐(dichlorophosphino) substituted 1, 3‐azaphospholo[5,1‐b]thiazoline (4) was obtained.The chemical shift of the two‐coordinate phosphorus in 1,3‐azaphosphole derivatives clearly reflects the influence of the heterocyclic system annulated to its 1,5‐bond and of the substi

ISSN:1042-7163    

DOI:10.1002/hc.520030408

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractBromine does not add to phosphorus in a 2‐phosphaindolizine1but substitutes its 1‐position. The 1‐bromo derivatives2are best prepared with Br2/NEt3or N‐bromosuccinimide. Their hydrolysis is remarkable; it involves a debromination of C‐1, an oxidation of P and a selective opening of the P/C‐3 bond.PCl3also causes a substitution of the 1‐position. The resulting 1‐dichlorophosphino derivatives5easily undergo a substituent exchange at the exocyclic phosphorus. More 1‐phosphino derivatives are formed in the reaction of1with phenyl and diazaphospholyl

ISSN:1042-7163    

DOI:10.1002/hc.520030409

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

Abstract2‐Benzylthio‐4,5‐benzo‐1,3,2‐dioxaphospholane reacts with oxygen to form the corresponding thiophosphonate, dithiophosphate and pyrophosphite. The reaction was found to be of a radical nature. The mechanism is suggested to involve an initial electron transfer with suitable subsequent transformations. The interaction of the title compound with various ketones in a pure oxygen atmosphere was studied by the CID

ISSN:1042-7163    

DOI:10.1002/hc.520030410

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY

摘要:

AbstractCo‐pyrolysis of thiophenol or diphenyl disulfide with tetrafluoroethylene or chlorotrifluoroethylene in the presence of oxidants gave 2,2,3,3‐tetrafluoro‐2,3‐dihydrobenzo[b]thiophene (I) or the corresponding chlorotrifluorodihydrobenzothiophenes.Reactions of compounds synthesized by use of electrophilic and nucleophilic reagents and with oxidants have been

ISSN:1042-7163    

DOI:10.1002/hc.520030411

出版商:VCH Publishers, Inc.    

年代:1992

数据来源: WILEY