Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 170. Synthese und Struktur eines 1,3,2,4-Diphosphadiboretans (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2681-2685 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 170. Synthesis and Structure of a 1,3,2,4-DiphosphadiboretaneDehydrohalogenation of chloro[(1,1-diethylpropyl)phosphino](2,2,6,6-tetramethylpiperidino)borane (1) produces no compound with a PB double bond but its diphosphadiboretane dimer 3, whose crystal structure has been determined. The molecule has a crystallographic center of symmetry. Its BP bond lengths (1.916, 1.933 Å) are comparatively long, suggesting weak BP bonds.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190825
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 216. Über die Komplexbildung von 1,3,2,4-Diphosphadiboretanen mit Pentacarbonylchrom sowie über die Darstellung und Reaktivität von Borylidenphosphan-Komplexen (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 875-887 
    Details
    ISSN: 0009-2940
    Keywords: 1,3,2,4-Diphosphadiboretanes, 2,4-bis(dialkylamino)- ; Boranes, (dialkylamino)bis(alkylphosphanyl)- ; Chromium, pentacarbonyl[2,3-bis(dialkylamino)1-1,3,2,4-diphosphadiboretane] complexes ; Chromium, pentacarbonyl[(2,2,6,6-tetramethylpiperidino)phosphane-P]- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 216[1]. - On the Complex Formation of 1,3,2,4-Diphosphadiboretanes with Pentacarbonylchromium and the Preparation and Reactivity of Borylidenephosphane Complexes2,4-Bis(dialkylamino)1-1,3,2,4-diphosphadiboretanes (R2NBP-CMe3)2 with sterically undemanding amino substituents are prepared together with the corresponding bis(phosphanyl)1-boranes R2NB(PHCMe3)2 by the reaction of R2NBCl2 with Li-P(H)CMe3. Complexes of 1,3,2,4-diphosphadiboretanes with one or two pentacarbonylchromium fragments were obtained by the reaction of the ligands with Cr(CO)5·THF or Cr(CO)5·NMe3. If substituents are sterically demanding, cycloreversion is observed with formation of [(aminoborylidene)1-phosphanyl-P]pentacarbonylchromium compounds tmpB=PR[Cr(CO)5] (10, 29) with an allene-like structure. Complex 29 may also be prepared by HCl elimination from tmp-B(Cl)-P(H)CMe3[Cr(CO)5] (34) with lithium diisopropylamide. This reaction can by reversed be the addition of HCl. The diphosphadiboretane 11 reacts with HCl, ethanol, and secondary amines with cleavage of all BP bonds. The X-ray structures of complexes (Et2NB - PCMe3)2[Cr(CO)5]2 (23) and (iPr2NB - PCEt3)2 [Cr(CO)5] (25) as well as of the diphosphadi-boretanes (Me2NB - PCMe3)2 (11) and (iPr2NB - PCEt3)2 (24) are presented. The intra ring angles of 23 remain almost unchanged upon complexation. In contrast, the B2P2 ring of 25 is slightly folded and its noncoordinated P atom approaches a planar environment.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Contributions to the chemistry of boron, 188. Synthesis and Structures of New 1,3,2,4-Diphosphadiboretanes (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 871-879 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Beiträge zur Chemie des Bors, 188.  -  Synthese und Strukturen Neuer 1,3,2,4-DiphosphadiboretaneDrei Methoden wurden zur Darstellung neuer Diphosphadiboretane entwickelt: a) Die baseninduzierte Elimierung von Halogenwasserstoff aus (Amino)phosphinobor-halogeniden, b) Tris-(trimethylsilyl)phosphan-Abspaltung aus R2N—B[P(SiMe3)2]2-Zwischenprodukten und c) Organylphosphan-Eliminierung aus Aminobis(organylphosphino)boranen R2N—B(PHR′)2. Die Molekülstrukturen von drei neuen 1,3,2,4-Diphosphadiboretanen (3, 4a, 4c) wurden mittels Röntgenbeugung bestimmt. Sie sind durch planare B2P2-Ringe charakterisiert. Die P-Substituenten stehen trans zueinander. Experimentelle Ergebnisse werden mit MNDO III Rechnungen verglichen; letztere ergeben eine geringe Aktivierungsbarriere (ΔE = 5 kcal/mol) für die Dimerisierung von H2N—B=PMe zu (H2N—BPMe)2.
    Notes: Three methods have been devised to prepare new diphosphadiboretanes: a) Base-induced hydrogen halide elimination from (amino)phosphinoboron halides precursors, b) tris(trimethylsilyl)-phosphane elimination from R2N—B[P(SiMe3)2]2 intermediates prepared in situ from combinations of R2N—B(Cl)—P(SiMe3)2 and LiP(SiMe3)2, and c) organylphosphane elimination from aminobis(organylphosphino)boranes R2N—-B(PHR′)2. The molecular structures of three new 1,3,2,4-diphosphadiboretanes (3, 4a, 4c) were determined by X-ray diffractometry. These are characterized by a planar four-membered B2P2 ring with the phosphorus substituents in trans positions. Their BP bonds represent single bond distances. Experimental results are compared with MNDO III calculations which reveal a low barrier (ΔE = 5 kcal/mol) for the dimerization of the boraphosphene H2N—B=PMe to the diphosphadiboretane (H2N—BPMe)2.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19881210510
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Contributions to the Chemistry of Boron, 205. Formation of Phosphinoborane Rings. A Reinvestigation of the Reaction of [(CH3)3Si]3P with Borane(3) (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1455-1460 
    Details
    ISSN: 0009-2940
    Keywords: Phosphine-borane adducts ; Phosphinoboranes trimeric ; Spiro boron heterocycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Combination of (Me3Si)3P and H3B·THF results in the formation of the known adduct (Me3Si)3P·BH3 (1). The complex undergoes dehydrosilylation above 100°C, and two ring compounds, [(Me3Si)2PBH2]3 (2) and P[(μ—H—B2—H2)]{(BH2)2[P(SiMe3)2]2}2 (3), are isolated. The crystal structures of the compounds are compared with those of other phosphinoboranes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19901230702
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Contributions to the Chemistry of Boron, 214. Synthesis and Reaction Chemistry of Aminophosphanylboranes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 379-397 
    Details
    ISSN: 0009-2940
    Keywords: Boranes, amino-, phosphanyl- ; Diphosphadiboretanes ; Triphosphatriborinanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aminochlorophosphanylboranes, (R2N)B(Cl)P(SiMe3)2 (1a  -  d) and (R2N)B(Cl)PH2 (2a  -  d), are obtained from elimination reactions between aminochloroboranes and LiP(SiMe3)2 and LiPH2, respectively. Selected reaction chemistry of (i1-Pr2N)B(Cl)P(SiMe3)2] (1a) with NH3, Me3SiN3, Cr(CO)5 · NMe3, and W(CO)5 · NMe3 is described. The azide (i1-Pr2N)B(N3)P(SiMe3)2 (12a) is stable at 25°C; however, thermolysis at 80°C provides a novel six-membered ring compound [(i1-Pr2N)BN(SiMe3)P(SiMe3)]2 (13a). The reaction of (Ph2N)B(Cl)P(SiMe3)2 (1b) with LiP(SiMe3)2 produces the only isolable bis(phosphanyl)borane (5b), while combination of (R2N)B(Cl)Ph2 with LiPH2 · DME yields new diphosphadiboretanes 6 {(R2N)BPH}2 (R2N=i1-Pr2N, Ph2N and tmp=2,2,6,6-tetramethylpiperidino) and triphosphatriborinanes 7 {(R2N)BPH}3 (R2N=(Me3Si)2N, Me2N and Et2N). Two salts, [(i1-Pr2N) DME]2 (8a) and [tmpLi · DME]2 (8c) (DME=ethylene glycol dimethyl ether) are also isolated. The results of molecular structure determinations for [(i1-Pr2N)Bn(SiMe3)P(SiMe3)]2 (13a), [tmpBPH]2 (4c), [tmpBPH]2 · Cr(CO)5 (7c), {[(Me3Si)2N]BPH}3 (4d), {[(Me3Si)2N]BPH}3 · Cr(CO)5 (7d), (Ph2N)B[P(SiMe3)2]2 (5b), and [(i1-Pr2N) · DME]2 (8a) are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 215. Darstellung und Reaktionen monomerer Tetraorganylphosphanylborane (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 611-618 
    Details
    ISSN: 0009-2940
    Keywords: Phosphanylboranes, tetraorganyl ; 1,3,2,4-Diphosphadiboracyclobutane ; Diboranes, μ1-phosphanyl- ; Thiophosphinate, S1-boryl ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Boron, 215[1]. - Synthesis and Reactions of Monomeric Tetraorganyl-phosphanyl-boranesThe reaction of diorganyl-chloroboranes with lithium diorganyl-or lithium bis(trimethylsilyl)phosphides leads to the monomeric phosphanylboranes tBu2BPtBu2 (1), tBu2BP(SiMe3)2 (2), 9-BBNPtBu2 (3), 9-BBNP(SiMe3)2 (4), and Cy2BPtBu2 (5). These species were studied by NMR-spectroscopic methods. For further characterization reactions of the compounds 1, 3, and 5 have been investigated. Heating of 1 and 5 results in the formation of the dimeric phosphanylboranes tBu(H)BPtBu2 (8) and Cy(H)BPtBu2 (9) by dehydroboration. Dimers 8 and 9 are present as cis- and trans1-isomers as confirmed by X-ray structure analyses. The trans1-isomer of 9 shows a planar (BP)2 four-membered ring, whereas the ring of the cis1-isomer of 8 is slightly folded. Furthermore, the reaction of 3 with 9H-9-BBN yields (μ1-H)(μ-tBu2P)[9-BBN]2 (14), whose bridged structure is proven by a crystal structure analysis. Oxidation of the phosphorus atom in 3 with sulfur leads to the S1-boryl thiophosphinate tBu2(S)PS-9-BBN (16).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Contribution to the Chemistry of Boron, 232Part 231: Ref.[1].. Formation, Structure and Reactions of a P,P′-Bi(1,3,2,4-diphosphadiboretane)Dedicated to Prof. Dr. O. J. Scherer on the occasion of his 60th birthday. (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 557-560 
    Details
    ISSN: 0009-2940
    Keywords: PC cleavage ; P,P′-Bi(1,3,2,4-diphosphadiboretane), 3,3′-di-tert-butyl-2,2′,4,4′-tetrakis-(tetramethylpiperidino)- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photolysis of the 1,3,2,4-diphosphadiboretane (tBuPBtmp)2 (1) in dilute toluene solution yields the bicyclic diphosphadiboretane 2. In concentrated toluene solution or in hexane, however, the P,P′-connected bi(diphosphadiboretane) 4 is also formed implying that the radical [tBuP(Btmp)2P] 3 is the first photolysis product. On further photolysis, 3 and 4 are converted into bicyclic 2 as the final product. Reduction of 4 with sodium-potassium alloy followed by silylation with Me3-SiCl leads to the 1,3,2,4-diphosphadiboretanes (tmpBP-SiMe3)2 and [HP(Btmp)2PSiMe3]2. In contrast to many 1,3,2,4-diboretanes, 4 in the absence of photon or thermal promotion does not react with Cr(CO)5 · THF, Fe2(CO)9, or Pd(PPh3)4. However, a mixture of Cr(CO)5 · THF and 4 on photolysis gives the known complex (tmpBP)2 · 2 Cr(CO)5.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961290513
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Contribution to the Chemistry of Boron, 238Part 237: See ref. Synthesis and Assembly Mechanism for Spirocyclic Cage Compounds Containing, B, P and Si Atoms (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 933-937 
    Details
    ISSN: 0009-2940
    Keywords: Boron ; Phosphorus ; Spiro compounds ; Cage compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 1-lithio · DME-2,4-bis(dialkylamino)-l,3,2,4-diphosphadiboretanes (1a, 1b) with SiCl4 followed by dehydrohalogenation with tBuLi produce spirocyclic compounds [(R2NB)2P2]2Si (2a, 2b). The compounds have been characterized by spectroscopic methods and X-ray crystallography. The assembly process has also been followed and one intermediate species [(iPr2NB)2P2][(iPr2NB)P(H)(iPr2NB)P]SiCl (3) has been isolated and fully characterized.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300719
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Beiträge zur Chemie des Bors, 196. Darstellung und Reaktionen eines 3-Amino-1,2,3-azaphosphaboriridins (1989)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 122 (1989), S. 423-426 
    Details
    ISSN: 0009-2940
    Keywords: 1,2,3-Azaphosphaboriridine, 3-amino- ; Chromium complex, (3-amino-1,2,3-azaphosphaboriridine-P)- ; 1,3,2,4-Thiazaphosphaboretidine-2-sulfide derivative ; Tungsten complex, (3-amino-1,2,3-azaphosphaboriridine-P)- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 196. - Preparation and Reaction of a 3-Amino-1,2,3-azaphosphaboriridineThe 1,2,3-azaphosphaboriridine 7, obtained by dehalogenation of the boryl(phosphino)amine precursor 6, reacts with sulfur or selenium not only with ring expansion but also with oxidation of its λ3-P atom to form the new heterocycles 8. The M(CO)5 fragments generated photolytically from Cr(CO)6 and W(CO)6, respectively, add to the P atom of 7. In contrast, MeI does not produce the phosphonium salt derived from 7. Rather the RP fragment is removed as iPr(Me)PI with formation of the iminoborane tmp-iPr.
    Notes: Das 1,2,3-Azaphosphaboriridin 7, dargestellt durch Enthalogenieren der Boryl(phosphino)amin-Vorstufe 6, reagiert mit Schwefel und Selen nicht nur unter Ringerweiterung, sondern zugleich unter Oxidation des λ3-Phosphors zu den neuen Heterocyclen 8. Während sich die aus Cr(CO)6 und W(CO)6 unter Photolyse erzeugten Pentacarbonylfragmente M(CO)5 an das P-Atom von 7 addieren, erhält man mit MeI kein Phosphoniumsalz. Vielmehr wird das RP-Fragment von 7 unter Bildung des Iminoborans tmp-tBu als iPr(Me)PI abgespalten.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19891220305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Synthesis and Structure of a Silyl-aminoalane Ring (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2649-2651 
    Details
    ISSN: 0009-2940
    Keywords: Alane, amino- ; Aluminium nitride ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of hydrazine with tris(trimethylsilyl)aluminium-ether have been studied: Reactant ratios of 0.5:1 and 0.8:1 produce the cyclic aminoalane [(Me3Si)2AlN(H)(SiMe3)]2 (1), which is formed by N-N bond cleavage and silyl group migration from aluminium to nitrogen. Pyrolysis under NH3 of a polymeric product formed from a 1:1 reaction produces an AlN/Si3N4 composite.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...