Showing papers on "Tetrahydrofuran published in 1997"
TL;DR: In this article, the vibrational properties of 1:1 neutral adducts were studied and the effect of the proton potential on the vibration of the adduct was analyzed.
Abstract: The interaction of Bronsted sites of H−β (AH) with bases B with proton affinity (PA) ranging in the 118 (N2) to 204 (NH3) kcal mol-1 interval leads to the formation of 1:1 adducts. The vibrational manifestations of these adducts change considerably as a function of the proton potential. In 1:1 neutral adducts characterized by weak-medium hydrogen bonds, the shift of the ν(AH) mode (Δν) is proportional to the shift caused by the same bases on the Si−OH (weak) Bronsted acid used as a standard. As far as the 1:1 adducts formed with ethers and tetrahydrofuran (THF; PA = 196 kcal mol-1), the situation is more complex owing to high ionicity acquired by the hydrogen bond. When stronger bases are used (pyridine, Py), the true proton transfer is observed. The ν(AH···B) modes of the medium-strong 1:1 adducts are modulated by Fermi resonances with 2δ and 2γ overtones and with internal modes of A and B moieties. A general review of the phenomenon is given. Also the spectra of the ionic 1:1 adducts formed with Py and...
214 citations
TL;DR: In this paper, the authors showed that tetrahydrofuran clathrate hydrate single crystals grow from the supercooled melt as octahedra, showing that {1 1 1} is the slowest growing face.
132 citations
TL;DR: In this article, the authors used NMR and Raman spectra in conjunction with the acute Si-Si-Si angles found in their molecular structures indicate mainly ionic bonding.
Abstract: Transmetalation reactions between bis(hypersilyl)zinc Zn[Si(SiMe3)3]2 and alkali metals have already been established as a facile route to powders of the solvent-free potassium, rubidium, and cesium derivatives of tris(trimethylsilyl)-silane (hypersilane, (Me3Si)3SiH).[1,2] By the use of boiling n-heptane as the solvent, the hitherto unknown NaSi(SiMe3)3 (1) along with the previously synthesized KSi(SiMe3)3 (2) have now been obtained as colorless crystalline materials. Information from NMR and Raman spectra in conjunction with the acute Si-Si-Si angles found in their molecular structures indicate mainly ionic bonding. This was verified by population analyses of suitable model systems. Both hypersilanides[2] consist of cyclic dimers [MSi(SiMe3)3]2 (1a, M = Na; 2a, M = K) with almost planar M2Si2 rings (Na-Si = 299 pm (av); K-Si = 339 pm (av)), which are linked up into coordination polymers. In a similar manner to the related rubidium and cesium derivatives, a pentane suspension of the potassium compound afforded a yellow solution on addition of benzene, from which the crystalline, bright yellow tris(benzene) solvate 2·(benzene)3 (2b) was isolated. Complex 2b consists of monomers containing short K-Si bonds (332–334 pm) and three η6-bonded benzene molecules. No solvate of 1 was obtained under these conditions. However, on crystallization from pure benzene, crystals of (1)2·benzene (1b) were isolated (Na-Si = 302 pm (av)). Benzene was found to be intercalated between rods of coordination polymers of (1)2. In addition, the influence of π or s donors on the molecular and crystal structures of hypersilylrubidium (3) and cesium (4) was investigated. The structures of the tetrahydrofuran solvate (4)2·THF (4c), the biphenylene/pentane complex (4)2·biphen·(pentane)0.5 (4b) along with the known toluene solvates (3)27dot;toluene (3a) and (4)2·(toluene)3 (4a)[1a] are compared. Finally, an example is presented of how the alkali metal hypersilanides could be utilized in preparing extremely bulky stannanide anions.
131 citations
TL;DR: In this paper, the behavior of the chemical species formed by the reduction of sulfur with alkali metals in nonaqueous solvent has not yet been clarified, but it is shown that polysulfide dianions (Sm2−, m > 1) and radical anions (Sn−, n ≥ 1) are in a state of equilibrium.
106 citations
TL;DR: The P-C-P pincer complex as mentioned in this paper is a pincher complex that catalyses the transfer dehydrogenation of the donor-bearing substrates, ethylbenzene and tetrahydrofuran at temperatures as low as 150 °C.
101 citations
TL;DR: The reaction of the participants was varied depending on the degree of electron deficiency and the co-ordination of the metal centres, and range from an average of 2056 A in 1 and 4 to 2169 A in 5 Complexes as discussed by the authors.
Abstract: The reaction of
C
6
H
10
(NLiSiMe
3
)
2
-1,2
(Li
2
L
1
) with
[ZrCl
4
(thf)
2
]
(thf = tetrahydrofuran) afforded the tetraamide
[ZrL
1
2
] 1 Similarly treatment of
(RHNSiMe
2
)
2
O (H
2
L
2
,
R = Bu
t
; H
2
L
3
,
R = cyclohexyl) with LiBu
n
followed by
[ZrCl
4
(thf)
2
] led to
[ZrL
2
2
] 2 and [ZrL
3
2
] 3,
respectively Reaction of Zr(CH
2
Ph)
4
with
H
2
L
3
gave the pale yellow zirconium dibenzyl
compound [Zr(CH
2
Ph)
2
L
3
] 4, while the
analogous reaction with H
2
L
4
(R = quinolin-8-yl) led to ruby-red
[Zr(CH
2
Ph)
2
L
4
] 5 In addition the
bis(pyrrole)
[(2-C
4
H
3
NH)CHNCH
2
]
2
(H
2
L
5
) reacted with
Zr(CH
2
Ph)
4
giving the complex
[Zr(CH
2
Ph)
2
L
5
] 6 The crystal
structures of 1, 4 and 5 have been determined Compound 1 has a
distorted tetrahedral structure In 4 and 5 all available donor atoms
co-ordinate to zirconium, including the silyl ether moiety, leading to a
distorted trigonal bipyramidal structure for 4 and an approximately
pentagonal bipyramidal geometry for 5 Although L
3
and
L
4
have flexible frameworks, in both 4 and 5 the heteroatom
donors and the metal form an essentially coplanar arrangement The
zirconium–amido nitrogen distances proved to be highly variable,
depending on the degree of electron deficiency and the co-ordination of
the metal centres, and range from an average of 2056 A in 1 and
2096 A in 4 to 2169 A in 5 Complexes 1 and 4 activated
with methylaluminoxane gave high molecular weight polyethylene with
moderate activity
99 citations
TL;DR: In this paper, the phase behavior of amphiphilic copolymer−alkanol−water ternary systems was investigated for triblock copolymers of similar molecular weight and the same hydrophilic block [poly(ethylene oxide), E] but having different hydrophobic blocks (poly(propylene oxide), P, or poly(n-butylene oxide) = poly(tetrahydrofuran), T].
Abstract: The phase behavior of amphiphilic copolymer−alkanol−water ternary systems was investigated for triblock copolymers of similar molecular weight and the same hydrophilic block [poly(ethylene oxide), E] but having different hydrophobic blocks [poly(propylene oxide), P, or poly(n-butylene oxide) = poly(tetrahydrofuran), T]. The alkanol used (butan-1-ol) was comparable in terms of chemical composition to the hydrophobic segments. A rich phase behavior was obtained for the polymer with the P middle block (Pluronic F127, E100P70E100): five different one-phase regions, i.e., micellar (L1) and reverse micellar (L2) solutions, and (micellar) cubic (I1), hexagonal (H1), and lamellar (Lα) lyotropic liquid crystalline regions, were detected. The microstructure in the liquid crystalline regions was established from small-angle X-ray measurements; I1 was found to be primitive cubic. The alkanol molecules are most likely anchored with their OH− group at the E−P interface, increasing the apparent volume of the P blocks r...
94 citations
TL;DR: A series of novel aromatic diamines (1-3) containing kinked cyclohexylidene moieties was synthesized by a reaction of excess aniline and corresponding methyl-substituted cycloenanone derivatives as mentioned in this paper.
Abstract: A series of novel aromatic diamines (1-3) containing kinked cyclohexylidene moieties was synthesized by a reaction of excess aniline and corresponding methyl-substituted cyclohexanone derivatives. The structures of (1-3) were identifield by 1 H NMR, 13 C NMR, and FT-IR. The polymers were synthesized from the obtained diamines and various aromatic dianhydrides by the conventional polycondensation reaction followed by chemical imidization as well as high-temperature one-step polymerization. The inherent viscosities and weight-average molecular weights of the resulting polyimides were in the ranges of 0.55-1.58 dUg and (7.4-15.2) x 10 4 g/mol, respectively. The prepared polyimides showed excellent thermal stabilities and good solubility. All polymers were readily soluble in common organic solvents such as tetrahydrofuran, chloroform, tetrachloroethane, etc., and the glass transition temperatures were observed at 290-372 °C.
85 citations
Patent•
10 Jul 1997
TL;DR: In this paper, a method for degrading an undesirable ether-based environmental contaminant by contacting the ether with a propane-oxidizing microorganism or with an isopropanoloxidising micro-organism to convert the ether to innocuous compounds which are environmentally acceptable was proposed.
Abstract: A method for degrading an undesirable ether-based environmental contaminant by contacting the ether with a propane-oxidizing microorganism or with an isopropanol-oxidizing microorganism to convert the ether to innocuous compounds which are environmentally acceptable, including treating the ether-based contaminants in situ or removing them from the contaminated site for treatment in a bioreactor, examples of the ether-based contaminants being tertiary butyl ethers of the type utilized as gasoline oxygenates, for example, methyl tert-butyl ether, ethyl tert-butyl ether, and methyl tert-amyl ether, and also ether solvents, for example, tetrahydrofuran, and including also means for monitoring the degradation of methyl tert-butyl ether by evaluating the treated contaminated media for degradative intermediates, for example, tert-butyl alcohol and 2-hydroxy isobutyric acid, and further including contacting the ether with a microorganism that is effective in oxidizing 2-hydroxy-isobutyric acid.
82 citations
TL;DR: In this article, the authors synthesized AxZrNCl (A = Li, Na, K) by the reaction of β-zirconium nitride chloride with n-butyllithium or the respective alkali metal naphthalenes.
Abstract: Alkali metal intercalated compounds AxZrNCl (A = Li, Na, K) were synthesized by the reaction of β-zirconium nitride chloride with n-butyllithium or the respective alkali metal naphthalenes. All of the compounds became superconductors with a transition temperature (Tc) of ca. 15 K. Polar solvent molecules such as tetrahydrofuran, dimethylformamide, and propylene carbonate were co-intercalated with the alkali metals, expanding the interlayer spacing. The Tc was dependent solely on the amount of intercalated alkali metals, or the doping level; the kind of intercalated alkali metals and the interlayer separation were not influential to the Tc. Although β-ZrNCl is a semiconductor, only a small amount of doping of alkali metals was necessary for the superconductivity. Too much doping with alkali metals resulted in the decrease of Tc down to ca. 9 K.
80 citations
TL;DR: In this paper, the thermal conductivity of 12 pure organic solvents, acetone, acetonitrile, acrylonitrile and carbon tetrachloride, chloroform, 1,2-dichloroethane, ethanol, ethyl acetate, heptane, tetrahydrofuran, toluene, and water, and eight binary mixtures, were measured by an absolute transient hot-wire method at some selected temperatures from 253.15 K to 303.15
Abstract: The thermal conductivity of 12 pure organic solvents, acetone, acetonitrile, acrylonitrile, carbon tetrachloride, chloroform, 1,2-dichloroethane, ethanol, ethyl acetate, heptane, tetrahydrofuran, toluene, and water, and eight binary mixtures, acetone + ethanol, acetone + ethyl acetate, ethanol + heptane, ethanol + carbon tetrachloride, ethyl acetate + ethanol, heptane + acetone, heptane + toluene, and water + ethanol, were measured by an absolute transient hot-wire method at some selected temperatures from 253.15 K to 303.15 K. A correlation previously developed was used to calculate the thermal conductivity. The agreement between the experimental and the calculated thermal conductivities is satisfactory.
TL;DR: In this article, the authors investigated the effect of the hydroxyl and pyridyl contents in the component polymers and found that the minimum content of the interaction groups required for complexation strongly depends on the solvent used.
Abstract: The complexation of poly(styrene-co-vinylphenol) (STVPh) and poly(styrene-co-vinylpyridine) (STVPy) in nonaqueous solution was investigated with emphasis on the effect of the hydroxyl and pyridyl contents in the component polymers. Viscometry, nonradiative energy transfer fluorospectroscopy, and dynamic laser light scattering have led to the same conclusion, i.e., STVPh and STVPy blend can form an interpolymer complex due to hydrogen bonding in tetrahydrofuran, butanone, and chloroform, provided the contents of the hydroxyl and pyridyl reach certain respective levels. The size distribution of the complex aggregates is relatively narrow with a peak size 1 order of magnitude larger than those of the component polymer coils. The minimum content of the interaction groups required for complexation strongly depends on the solvent used. Chloroform and butanone are almost inert for hydrogen bonding between the polymers, tetrahydrofuran has a substantial influence on complexation, and addition of N,N-dimethylforma...
TL;DR: In this paper, two samples of poly[3-(6-methoxyhexyl)-2,5-thienylene] with a slight difference in regioregularity and a greater difference in molecular weights were obtained by chemical oxidation with FeCl3.
TL;DR: In this article, Liss et al. showed that polyphenylacetylenes bearing an amino group exhibited an induced circular dichroism (ICD) in the UV-visible region, probably due to a prevailing one-handed helical conformation upon complexation with optically active carboxylic and α-hydroxy acids.
TL;DR: In this paper, the α-C−H bond dissociation energy (BDE) in 1,2,3,4-tetrahydronaphthalene (tetralin) in the neat liquid was determined in comparison with hydrogen abstraction from tetrahydrofuran (THF).
Abstract: Photoacoustic Calorimetry is used to determine the α-C−H bond dissociation Energy (BDE) in 1,2,3,4-tetrahydronaphthalene (tetralin) in the neat liquid as well as in competition with hydrogen abstraction from tetrahydrofuran (THF) Also, the α-C−H BDE in THF was determined in the neat liquid The experiments with the mixtures of tetralin and THF and with the neat liquids lead to the same results BDEgas(tetralin) is found to be 829 ± 12 and BDEgas(THF) to be 921 ± 16 kcal mol-1 The revised global rate constant of hydrogen abstraction from THF is found to be 46 × 106 M-1 s-1 at 297 K
TL;DR: A series of magnesium-isothiocyanate and carbodiimide compounds were used in this article to construct the 1, 3, 8, 9 and 11 complexes.
Abstract: A series of magnesium–isothiocyanate and –carbodiimide
insertion products, Mg(SCPhNBu
t
)
2
(thf)
2
1, Mg(SCPhNPh)
2
(thf)
2
2,
Mg(Pr
i
NCRNPr
i
)
2
(thf)
2
(R = Ph 3, Et 4 or Pr
i
5) and
Mg(Bu
t
NCEtNBu
t
)
2
(thf)
2
6 have been prepared by the stoichiometric reaction between
MgR
2
(R = Ph, Et or Pr
i
) and various
isothiocyanates and carbodiimides in tetrahydrofuran (thf) solution. The
1∶1 reaction between bis(diisopropylamido)magnesium and
1,3-diisopropylcarbodiimide gave a dinuclear complex
Mg
2
(µ-NPr
i
2
)
2
[(Pr
i
N)
2
CNPr
i
2
]
2
7
and a mononuclear complex
Mg[(Pr
i
N)
2
CNPr
i
2
]
2
(thf) 8 when the stoichiometry is 1∶2. The
mononuclear complexes
Mg[SC(NPh)NR
2
]
2
(thf)
2
(R = Pr
i
9 or Et 10) were
obtained using phenyl isothiocyanate and bis(diethylamido)- or
bis(diisopropylamido)-magnesium in 1∶1 stoichiometric ratio. A
plausible mechanism for the formation of 7 and 8 is
suggested. Reaction between MgEtBr and PhNCS in diethyl ether gave the
dinuclear complex
Mg
2
(SCEtNPh)
4
(OEt
2
)
2
11. All of the complexes were characterized by 1
H,
13
C NMR and IR spectroscopy as well as elemental analysis.
The crystal structures of 1, 3, 8, 9
and 11 were determined by single-crystal X-ray diffraction. The
reaction of complex 1 with an excess of PhNCO resulted in the
cyclotrimerization of phenyl isocyanate to give
(PhNCO)
3
·thf.
TL;DR: The first dialkylead(II) species to be structurally characterized is the title lead (II) derivative, obtained as dark blue crystals by treatment of PbCl2 with (TMEDA = N,N,NN, N'N', N'Tetramethylethylenediamine) in tetrahydrofuran and its structure determined by X-ray diffraction as mentioned in this paper.
TL;DR: In this article, the structure of a two-dimensional cross-linked polymeric chain with tetrahydrofuran (THF) adducts was characterized by X-ray crystallography.
Patent•
08 Apr 1997
TL;DR: In this paper, an oximesulfonate compound of the formula was obtained by subjecting an oxime group-containing compound to esterification reaction with a sulfonic chloride groupcontaining compound in an organic solvent such as tetrahydrofuran in the presence of a basic catalyst such as pyridine.
Abstract: PROBLEM TO BE SOLVED: To obtain the subject new compound useful as an acid generator for a resist, having high transparency to active light used for light exposure and high in strength of generated acid and especially excellent in solubility to resist solvent. SOLUTION: This acid generator is an oximesulfonate compound of the formula (R and R are each a nonaromatic hydrocarbon or a halogenated nonaromatic hydrocarbon), e.g. α-(methylsulfonyloxyimino)-1 cyclopentenylacetronitrile. In the compound of the formula, preferably, R is a cycloalkenyl and R is an alkyl, especially preferably, R is a cyclopentenyl or a cyclohexenyl and R is a 1-4C lower alkyl. Furthermore, the compound of the formula is obtained by subjecting, e.g. an oxime group-containing compound to esterification reaction with a sulfonic chloride group-containing compound in an organic solvent such as tetrahydrofuran in the presence of a basic catalyst such as pyridine.
TL;DR: In this article, the crystal structure of bis[triphenylphosphane)gold(I)]bromonium tetrafluoroborate was determined by single-crystal X-ray diffraction.
Abstract: Reactions of (R3P)AuX (X = Cl, Br, I) with [(R3P)Au]+ BF−4 obtained from (R3P)AuCl and AgBF4 in tetrahydrofuran, lead to cationic binuclear gold(I) complexes of the general formula ([(R3P)Au]2X}+ BF−4. A number of chloro- (R = Ph, o-Tol, Mes, Bzl, Et), bromo- (R = Ph, o-Tol, Mes) and iodo-bridged (R = Ph, Mes) complexes of this type have been isolated and identified on the basis of their analytical and spectroscopic data. The crystal structure of bis[(triphenylphosphane)gold(I)]bromonium tetrafluoroborate was determined by single-crystal X-ray diffraction. The cations contain two-coordinate bromine atoms with an Au-Br-Au angle of 96.83(3)°.
TL;DR: In this paper, the equilibrium ratios for the zwitterionic and neutral forms of the nicotinic and isonicotinic acids (3- and 4-COOH pyridines) have been determined by spectrophotometry in mixtures of water with methanol, tetrahydrofuran and dioxane.
Abstract: The equilibrium ratios for the zwitterionic and neutral forms of the nicotinic and isonicotinic acids (3- and 4-COOH pyridines) have been determined by spectrophotometry in mixtures of water with methanol, tetrahydrofuran and dioxane. The zwitterionic form of the solute is the prevalent structure in mixtures with at least 60% water. In pure organic solvents, the neutral form was found in almost 100%. Ab initio calculations at the MP2/6-311++G**//MP2/6-31G* level predict that the zwitterion is higher in free energy by 33−35 kcal/mol than the neutral tautomer at T = 298 K and p = 1 atm in the gas phase. In contrast, relative solvation free energies, as calculated by the free energy perturbation method in Monte Carlo simulations, are −36, −27, and −15 kcal/mol in water, methanol, and tetrahydrofuran, respectively. The solvent effects for overbalancing the relative internal free energy of the zwitterion and stabilizing this tautomer are large enough only in water and in aqueous solution with water fraction ab...
TL;DR: In this article, the Mercury(II) amide complex Hg[N(SiMe3)(2,6-iPr2C6H3)]2 (1) was prepared by reaction of HgBr2 with Li[N[NMe3) 2.6-IPr2c6h3]2(THF) in diethyl ether solvent.
Abstract: The Mercury(II) amide complex Hg[N(SiMe3)(2,6-iPr2C6H3)]2 (1) was prepared by reaction of HgBr2 with Li[N(SiMe3) 2,6-iPr2C6H3)] in diethyl ether solvent. Redox transmetallation reactions of 1 with elemental samarium, europium or ytterbium in THF solvent (THF = tetrahydrofuran), generated the novel divalent complexes Ln[N(SiMe3)(2,6-iPr2C6H3]2(THF)2 with Ln = Sm (2), Eu (3) and Yb (4). 4 was also synthesized by reaction of elemental ytterbium, HgPh2 and HN(SiMe3)(2,6-Me3)2]2(THF)2 [Ln = Sm (5), Yb (6)] by reaction of the metals with HgPh2 and HN(SiMe3)2. Thermal desolvation of 4 under high vacuum gave Yb(N)(SiMe3)2,6-iPr2C6H3)]2 (THF) (7), whereas under identical conditions 6 yielded the solvent-free complex [Yb[N{SiMe3)2]2]2. (8). The new compounds 1–4 and 7 are hydrocarbon soluble and 171Yb-NMR spectra were recorded for 4, 6, 7 and 8. X-ray crystal structure determinations of 2 and 4 revealed four-coordinate, distorted tetrahedral metal environments augmented by weak Ln…ipso-C(aryl) interactions.
TL;DR: In this article, the structural data of these complexes satisfactorily explain the hmpa effects observed in SmI2-promoted reactions, and also provide a guideline for the use of HMPA in these reactions.
Abstract: The reaction of ytterbium(II) iodide (YbI2) with 4.5 equiv of hexamethylphosphoric triamide (hmpa) in tetrahydrofuran (thf) gave [Yb(hmpa)4(thf)2]I2 (1) as yellow crystals. A similar reaction of SmI2 with hmpa afforded black-purple [SmI2(hmpa)4] (2) after recrystallization from toluene. When 10 equiv of hmpa were used in the reaction with SmI2, [Sm(hmpa)6]I2 (3) was obtained as purple blocks. Complexes 1—3 have been structurally characterized by crystallographic studies. The structural data of these complexes satisfactorily explain the hmpa effects observed in SmI2-promoted reactions, and also provide a guideline for the use of HMPA in these reactions.
TL;DR: Reactivity of D-amino acid amides as acyl acceptors and partially unblocked amino acid acyl donors further expands the generality of the use of organic solvent-soluble enzymes as peptide synthesis catalysts.
TL;DR: Several aromatic Noxides such as pyrazine, arylpyridine and quinoline N-oxides have been deoxygenated to parent amines under mild and efficient conditions using zinc and aqueous ammonium chloride in tetrahydrofuran as mentioned in this paper.
Abstract: Several aromatic N-oxides such as pyrazine, arylpyridine and quinoline N-oxides have been deoxygenated to parent amines under mild and efficient conditions using zinc and aqueous ammonium chloride in tetrahydrofuran.
TL;DR: In this article, the first cycloheptatrienyl compound, tetrahydrofuran, has been determined and the reaction of the neutral compound has been analyzed.
Abstract: Reaction of UX
4
(X = NEt
2
or
BH
4
) with K[C
7
H
9
] afforded the anionic
complexes
K[X
3
U(µ-η
7
∶η
7
-C
7
H
7
)UX
3
] whereas treatment of
[Nd(BH
4
)
3
(thf)
2
]
(thf = tetrahydrofuran) with K[C
7
H
9
]
gave the neutral compound
[(thf)(BH
4
)
2
Nd(µ-η
7
∶η
7
-C
7
H
7
)Nd(BH
4
)(thf)
2
]. The formation of the
cycloheptatrienyl ligand resulted from the disproportionation reaction 3
C
7
H
9
-
→ C
7
H
7
3-
+ 2
C
7
H
10
. The crystal structure of
[(thf)(BH
4
)
2
Nd(µ-η
7
∶η
7
-C
7
H
7
)Nd(BH
4
)(thf)
3
], the first cycloheptatrienyl compound
of a 4f element, has been determined.
TL;DR: The tetrahydrofuran complexes of the alkaline earth metal bis[bis(trimethylsilyl)phosphanides] react with 2 equiv of benzonitrile to the bis[1,3-bis-2-phenyl-1-aza-3-phosphapropenides] of magnesium (1), calcium (2), strontium (3), and barium (4).
Abstract: The tetrahydrofuran complexes of the alkaline earth metal bis[bis(trimethylsilyl)phosphanides] react with 2 equiv of benzonitrile to the bis[1,3-bis(trimethylsilyl)-2-phenyl-1-aza-3-phosphapropenides] of magnesium (1), calcium (2), strontium (3), and barium (4). Whereas 1 and 2 crystallize as bis(tetrahydrofuran) adducts, the heavier homologous derivatives 3 and 4 precipitate as tris(tetrahydrofuran) complexes. The bidentate trans/trans-isomeric 1,3-bis(trimethylsilyl)-2-phenyl-1-aza-3-phosphapropenide ligands of all these compounds display very similar spectroscopic data; however, the influence of the alkaline earth metal is observed in the silicon NMR. The nitrogen atoms of these anions have trigonal planar geometry, whereas the phosphorus atoms are coordinated trigonal pyramidal. Crystallographic data: 1, monoclinic, P21/c, a = 1505.3(3) pm, b = 1259.0(2) pm, c = 2278.4(5) pm, β = 91.91(2)°, Z = 4, wR2 = 0.1279; 2, monoclinic, P21/c, a = 1522.8(7) pm, b = 1279.2(5) pm, c = 2314.0(10) pm, β = 92.53(2)°...
TL;DR: In this paper, Dimethylethylamine−alane (DMEAA) reacted with 2,6-diisopropylphenol (DIPH) in THF at −78 °C to give DIP2AlH·2THF (1) in 94% yield.
Abstract: Dihydrogen elimination from aluminum hydrides and alcohols was used to produce new alkoxide and aryloxide complexes. Dimethylethylamine−alane (DMEAA) reacted with 2 equiv of 2,6-diisopropylphenol (DIPH) in THF at −78 °C to give (DIP)2AlH·2THF (1) in 94% yield. It was characterized by NMR, IR, MS, and X-ray crystallography and found to be trigonal bipyramidal with both axial sites occupied by THF. Crystal data for 1: C32H51AlO4, monoclinic, C2/c, a = 21.37(1) A, b = 9.324(3) A, c = 15.30(1) A, β = 94.16(5)°, V = 3040(5)A3, Z = 4. DMEAA reacted with 2 equiv of triphenylcarbinol, Ph3COH, in THF at −78 °C to give (Ph3CO)2AlH·THF (2) in 42% yield. The lower coordination number was attributed to the larger cone angle of the ligand. Crystal data for 2: C42H39AlO3, triclinic, P1, a = 8.482(1) A, b = 9.067(1) A, c = 23.59(1) A, α = 90.919(1)°, β = 92.624(1)°, γ = 116.093(1)°, V = 1626.2(2) A3, Z = 2. Three equivalents of DIPH in THF reacted with DMEAA at −78 °C to form the unexpected compound (DIP)3(THF)(NMe2Et...