Donor-Acceptor Complexes between Organoamines and Phosphorus Tribromide

2001 ◽  
Vol 56 (11) ◽  
pp. 1163-1171 ◽  
Author(s):  
Gerhard Müller ◽  
Jörg Brand ◽  
Simone Elisabeth Jetter
Keyword(s):  
Lewis Acid ◽  
Phosphorus Atom ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Ionic Character ◽  
Crystal Data ◽  
Acid Base ◽  
Crystal And Molecular Structures ◽  
Phosphorus Tribromide ◽  
Donor Acceptor

Lewis acid-base adducts between NMe3, tmeda (N ,N ,N′ ,N′-tetramethylethylenediamine), and 1.4-dimethylpiperazine as donors and PBr3 as acceptor have been prepared and structurally characterized. NMe3 and tmeda form 1:1 adducts (Me3N)PBr3 (1) and (tmeda)PBr3 (2), respectively, while 1,4-dimethylpiperazine adds 2 molecules of PBr3 leading to [(1,4-dimethylpiperazine)( PBr3)2] (3). Adduct 2 is found in two modifications 2a and 2b with different crystal and molecular structures. (Crystal data of 1: monoclinic P21/n, a = 5.983(3), b = 10.821(2), c = 13.877(5) Å, ß = 99.70(2)°, Z = 4. 2a: monoclinic P21/c, a = 7.891(1), b = 12.826(1), c = 12.218(2) Å ,ß = 102.162(6)°, Z = 4. 2b: monoclinic P21/n, a = 11.687(2), b = 8.375(1), c = 12.668(1) Å, ß = 102.74(1)°, Z = 4. 3: monoclinic P21/c, a = 6.383(3), b = 16.36(3), c = 8.407(3) Å , ß = 101.49(2)°, Z= 2). The molecular structures of 1 and 2 indicate a partially ionic character with a strongly bonded amine and one (1 ) or two (2 ) weakly bonded bromine atoms. In 2 the donor tmeda is bonded through both nitrogen atoms to one phosphorus atom. In 3 the 1,4-dimethylpiperazine ring is in chair conformation, the methyl and PBr3 substituents being in equatorial and axial positions, respectively. Due to axial-axial repulsion the N-P donor-acceptor bonds are long while the P-Br bonds are rather uniform in length.

Diorganogallium β-Diketonates and Their Lewis Acid−Base Adducts. Crystal and Molecular Structures of Mes2Ga(hfac) and Me2Ga(hfac)·NC5H5

1998 ◽  
Vol 17 (6) ◽  
pp. 1101-1108 ◽  
Author(s):  
O. T. Beachley, ◽  
James R. Gardinier ◽  
Melvyn Rowen Churchill ◽  
Laurence M. Toomey
Keyword(s):  
Lewis Acid ◽  
Molecular Structures ◽  
Acid Base ◽  
Crystal And Molecular Structures

scholarly journals Binding Properties of a Dinuclear Zinc(II) Salen-Type Molecular Tweezer with a Flexible Spacer in the Formation of Lewis Acid-Base Adducts with Diamines

Inorganics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 49
Author(s):  
Gabriella Munzi ◽  
Giuseppe Consiglio ◽  
Salvatore Failla ◽  
Santo Di Bella
Keyword(s):  
Lewis Acid ◽  
Degrees Of Freedom ◽  
Binding Constants ◽  
Molecular Structures ◽  
Acid Base ◽  
Binding Properties ◽  
Binding Characteristics ◽  
Fluorescence Studies ◽  
Flexible Spacer ◽  
Molecular Tweezer

In this paper we report the binding properties, by combined 1H NMR, optical absorption, and fluorescence studies, of a molecular tweezer composed of two Zn(salen)-type Schiff-base units connected by a flexible spacer, towards a series of ditopic diamines having a strong Lewis basicity, with different chain length and rigidity. Except for the 1,2-diaminoethane, in all other cases the formation of stable 1:1 Lewis acid-base adducts with large binding constants is demonstrated. For α,ω-aliphatic diamines, binding constants progressively increase with the increasing length of the alkyl chain, thanks to the flexible nature of the spacer and the parallel decreased conformational strain upon binding. Stable adducts are also found even for short diamines with rigid molecular structures. Given their preorganized structure, these latter species are not subjected to loss of degrees of freedom. The binding characteristics of the tweezer have been exploited for the colorimetric and fluorometric selective and sensitive detection of piperazine.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

Kristall- und Molekülstrukturen von zwei trans-1.2.4.5-Tetraza-3.6-diphospha-cyclohexan-3.6-disulfiden / Crystal and Molecular Structures of Two trans- 1,2,4,5-Tetraza-3,6-diphospha-cyclohexane-3,6-disulfides

1984 ◽  
Vol 39 (3) ◽  
pp. 269-274 ◽  
Author(s):  
Franz Dirschl ◽  
Heinrich Nöth
Keyword(s):  
Chair Conformation ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Torsion Angles ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Twist Conformation

The crystal and molecular structures of two trans-1,2,4,5-tetraza-diphospha-3,6-cyclohexane- 3,6-disulfides, 2 and 3, have been determined by X-ray diffraction methods. The 3,6-diphenyl- 1,2,4,5-tetramethyl-derivative 2 crystallizes in the monoclinic system, space group C He. Its P2N 4 heterocycle adopts a twist conformation. In contrast, the hexamethyl derivative 3 is triclinic, space group P1̅, and its ring shows chair conformation. Torsion angles in these two compounds and similar ones reveal less interaction between lone pairs of electrons on adjacent N-atoms in the chair conformation but stronger interaction of those bound to phosphorus. It is suggested that the latter interaction is responsible for the larger N -P -N bond angle (107°) as compared to the smaller one (101°) in the P2N4 rings present in twist conformation.

Formation of heterocyclic arylboronates by thermally induced 1,4-aryl migration in diarylboron chelates of C-(1-hydroxyalkyl)nitrones. Crystal and molecular structures of some of the rearrangement products and of one of the educts

2001 ◽  
Vol 79 (2) ◽  
pp. 226-237
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Jens O Pokriefke ◽  
Steven J Rettig ◽  
James Trotter
Keyword(s):  
Spectroscopic Data ◽  
Direct Methods ◽  
Molecular Structures ◽  
Time Dependent ◽  
Isomerization Reaction ◽  
Crystal Data ◽  
Thermally Induced ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Transition State Geometry

Synthesis of heterocyclic arylboronates has been carried out by thermally induced rearrangement of diarylboron chelates of C-(1-hydroxyalkyl)nitrones. The structures have been determined from spectroscopic data and from X-ray analyses. Thermoanalytical and time-dependent NMR measurements give information on the nature of the isomerization reaction. Crystal data (at 293 K for 2j, 180 K for the others): 1m, monoclinic, P21/n, a = 14.059(3), b = 12.5531(13), c = 14.8531(6) Å, β = 95.8067(12)°, Z = 4; 2j, triclinic, [Formula: see text]1, a = 10.4729(11), b = 13.5896(11), c = 9.5803(7) Å, α = 104.764(6), β = 103.279(7), γ = 107.278(7)°, Z = 2; 2m, monoclinic, P21/n, a = 14.9442(13), b = 11.990(2), c = 16.0613(4) Å, β = 114.0153(7)°, Z = 4; 9, monoclinic, P21/n, a = 11.123(2), b = 18.433(3), c = 13.4852(4) Å, β = 108.2075(7)°, Z = 4. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R(F, I [Formula: see text] 3σ(I)) = 0.036, 0.052, 0.043, and 0.040, respectively, for AFC6 data for 2j and CCD data for 1m, 2m, and 9. All four molecules contain six-membered OBONCC rings, with an approximately planar ON=CC segment in the educt 1m and approximately planar OBOC segments in the rearrangement products. A probable transition state geometry is derived for the isomerization process.Key words: diarylboron chelates, C-(1-hydroxyalkyl)nitrones, heterocyclic arylboronates, organoboron compounds, rearrangement, crystal structures.

Crystal and Molecular Structures of the Functional Lithium Cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph, Me

2000 ◽  
Vol 55 (11) ◽  
pp. 1005-1010 ◽  
Author(s):  
Ulrich Jürgen Bildmann ◽  
Martin Winkler ◽  
Gerhard Müller Fachbereich
Keyword(s):  
Solid State ◽  
Functional Group ◽  
Molecular Structures ◽  
The Other ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal and molecular structures of the phosphinomethyl-substituted lithium cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph (1), Me (2) (tmeda = N,N,N',N'-tetramethylethylenediamine) were determined as their tmeda adducts on the basis of low temperature single crystal X-ray diffraction. (Crystal data: 1: monoclinic, space group P21/n, a = 8.511(5), b = 11.936(2), c = 24.20(1) Å, β = 90.02(3)°, Z = 4.2: monoclinic, space group P21/n, a = 10.887(2), b = 13.326(2), c = 13.131(2) Å, β= 92.872(6)°, Z = 4). In both compounds lithium has a slightly distorted 17 coordination to the cyclopentadienide (Cp) ring. There are no interactions between lithium and the phosphine donors in the solid state as the phosphinomethyl substituents are oriented to the other side of the Cp ring for steric reasons. The isopropene-substituted lithium cyclopentadienide, which is formed as a by-product in the synthesis of phosphinomethyl cyclopentadienides containing a CMe2 bridge, was also structurally characterized as its tmeda adduct [Li(tmeda)][H2C=CMeC5H4] (3). (Crystal data: monoclinic, P21/c, a = 8.00(2), b = 16.701(2), c = 11.942(6) Å, β= 112.68(7)°, Z = 4). As in 1 and 2, lithium is η5 -coordinated to the Cp ring, and there is no interaction of the functional group (isopropene) with lithium.

Syntheses and properties of phosphino- and phosphinatopyrroles

1976 ◽  
Vol 54 (17) ◽  
pp. 2706-2709 ◽  
Author(s):  
Sven Fischer ◽  
James Hoyano ◽  
Ian Johnson ◽  
Louis K. Peterson
Keyword(s):  
Lewis Acid ◽  
Phosphorus Atom ◽  
Spectroscopic Data ◽  
Phosphonium Salt ◽  
Molecular Structures ◽  
Insertion Reactions ◽  
Hindered Rotation ◽  
Strong Base ◽  
Nucleophilic Displacement

The syntheses of P—N bonded pyrrolyl- and 2,5-dimethylpyrrolylphosphines [Formula: see text] (x = 0–2) and the oxy derivatives py3PO and (Me2py)2P(O)Cl by the reaction of potassium pyrrolide or 2,5-dimethylpyrrolide with an appropriate chlorophosphine or with POCl3 are described. Molecular structures were inferred from spectroscopic data. The P—N bonded phosphines are stable to solvolytic attack by water or alcohols and do not undergo insertion reactions with CS2, but they are oxidised by oxygen and suffer nucleophilic displacement of the azole moiety by strong base. The Lewis acid BCl3 cleaves the P—N bond and CH3I reacts with only one member, [Formula: see text] to form a phosphonium salt. Hindered rotation about the P—N bond was detected in the (2,5-dimethylpyrrolyl)phosphine series, but not among the corresponding oxy derivatives. The nature of the P—N bond and trends in the basicity of the phosphorus atom are discussed.

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