Synthesis and characterization of titanium complexes containing phosphinimido and tropidinyl ligands: Crystal structure of (trop)(t-Bu3PN)TiCl2

2002 ◽  
Vol 80 (11) ◽  
pp. 1618-1624 ◽  
Author(s):  
Steve J Brown ◽  
Xiaoliang Gao ◽  
Matthew G Kowalchuk ◽  
Rupert E.v.H. Spence ◽  
Douglas W Stephan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Synthesis And Characterization ◽  
Metallocene Catalysts ◽  
High Temperature Solution ◽  
Titanium Complexes ◽  
X Ray ◽  
X Ray Crystallography ◽  
New Class ◽  
Temperature Solution

A new class of titanium complexes containing a tropidinyl (trop) ligand and a phosphinimido (R3P=N-) or a ketimide ligand (R2C=N-) were synthesized and characterized. The combination of the cyclopentadienyl equivalent tropidinyl and phosphinimido ligands enables the formation of a group of novel non-metallocene catalysts for olefin polymerization. The crystal structure of (trop)(t-Bu3PN)TiCl2 was determined by single crystal X-ray crystallography. Polymerization of ethylene with this complex was studied in a high-temperature solution process.Key words: tropidinyl, phosphinimido, ketimide, catalyst, polymerization.

Synthesis and characterization of three new rare-earth orthoborates: Ba2MgY2(BO3)4, Ba2CdY2(BO3)4, and Ba2CdSc(BO3)3

2020 ◽  
Vol 49 (31) ◽  
pp. 10874-10879
Author(s):  
Runqing Liu ◽  
Hongping Wu ◽  
Hongwei Yu ◽  
Zhanggui Hu ◽  
Jiyang Wang ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Solution Method ◽  
Synthesis And Characterization ◽  
High Temperature Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Solution ◽  
First Time

Three rare-earth orthoborates Ba2MgY2(BO3)4, Ba2CdY2(BO3)4, and Ba2CdSc(BO3)3 were synthesized via a high-temperature solution method and their structures were determined by single crystal X-ray diffraction for the first time.

The synthesis and characterization of 3,3-disubstituted pent-4-enals and their 2,2-(trimethylenedithio)pent-4-enal precursors, including the X-ray crystal structure of (R)-3-ethyl-3-phenyl-2,2-(trimethylenedithio)pent-4-enal

1985 ◽  
Vol 63 (5) ◽  
pp. 1035-1040 ◽  
Author(s):  
Charles G. Young ◽  
Brian R. James ◽  
Steven J. Rettig
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Synthesis And Characterization ◽  
Intramolecular Rearrangement ◽  
X Ray ◽  
X Ray Crystallography ◽  
New Compounds ◽  
Allylic Bromide

A variety of 3,3-disubstituted pent-4-enals (5a, R = Me, R′ = Et; 5b, R = Me, R′ = Ph; 5c, R = Et, R′ = Ph) has been prepared by the Raney nickel desulfurization of the corresponding 3,3-disubstituted 2,2-(trimethylenedithio)pent-4-enal precursors 4a–4c. The precursor compounds were prepared by the alkylation of 2-formyl-1,3-dithiane with the appropriate 3,3-disubstituted allylic bromide. The new compounds have been characterized by elemental analysis, infrared and nmr spectroscopy, and mass spectrometry. The crystal and molecular structure of (R)-4c has also been determined by X-ray crystallography. At temperatures of ca. 130 °C, compounds 4a–4c undergo intramolecular rearrangement to form the tri-substituted alkenes 6a–6c, which have also been characterized by the present study.

Preparation and characterization of a new series of Cr(II) hydroborates

1995 ◽  
Vol 73 (7) ◽  
pp. 1126-1134 ◽  
Author(s):  
Michel Dionne ◽  
Shoukang Hao ◽  
Sandro Gambarotta
Keyword(s):  
Trinuclear Complex ◽  
Synthesis And Characterization ◽  
Crystal Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Quadruple Bond ◽  
Quadruple Bonds ◽  
Reaction Proceeds

The synthesis and characterization of a new series of mono-, di-, and trinuclear Cr(II) borohydride compounds is described. The reaction of CrCl2(TMEDA) with two equivalents of NaBH4 afforded the thermally unstable (TMEDA)Cr(BH4)2 (1), which was converted by treatment with pyridine into the octahedral monomeric (Py)4Cr(BH4)2 (2). The reaction proceeds via formation of an intermediate trinuclear complex {[(TMEDA)(Py)Cr(η2-BH4)]2[(Py)2Cr(η2-BH4)2]}(µ,η1-BH4)2 (3), which was isolated and characterized by X-ray crystallography. Reaction of 1 and 2 with both CO2 and RN=C=NR (R = Cy, iPr) afforded hydride insertion and formation of the corresponding diamagnetic lantern-type Cr(II) formate (HCO2)4Cr2Py2 (4) and formamidinate compounds [RNC(H)NR]2Cr2(µ-BH)4 (R = Cy (5a), iPr (5b)), respectively, with supershort Cr—Cr quadruple bonds. The structures of 1, 2, 3, and 5b were elucidated by X-ray analysis. Crystal data are as follows. 1: C6H24N2B2Cr, monoclinic, Cc, a = 8.517(2) Å, b = 15.921(5) Å, c = 9.624(2) Å, β = 115.59(1)°, Z = 4, R = 0.022, Rw = 0.029; 2: C28H44N4B2O2Cr, monoclinic, P21/n, a = 12.021(1) Å, b = 15.555(1) Å, c = 15.723(1) Å, β = 90.13(2)°, Z = 4, R = 0.074, Rw = 0.086; 3: C32H76N8B6Cr3, monoclinic, P21/n, a = 8.515(1) Å, b = 14.525(1) Å, c = 18.286(2) Å, β = 91.38(1)°, Z = 2, R = 0.051, Rw = 0.060; 5b: C21H49N6BCr2, monoclinic, C2/c, a = 17.000(1) Å, b = 9.033(1) Å, c = 19.160(1) Å, β = 105.579(9)°, Z = 4, R = 0.069, Rw = 0.078. Keywords: divalent chromium, borohydride, Cr—Cr quadruple bond.

Synthesis and characterization of the binuclear diamido titanium chalcogenides [(Ar)NCH2CH2CH2N(Ar)]2Ti(µ-E)2 (E = Se, Te)

2002 ◽  
Vol 80 (11) ◽  
pp. 1524-1529 ◽  
Author(s):  
Tianle Zhang ◽  
Warren E Piers ◽  
Masood Parvez
Keyword(s):  
Solid State ◽  
Key Words ◽  
Synthesis And Characterization ◽  
Catalyst Precursor ◽  
Tellurium Atom ◽  
Titanium Complex ◽  
X Ray ◽  
X Ray Crystallography ◽  
Atom Source

Reaction of McConville's chelating amido titanium complex [(Ar)NCH2CH2CH2N(Ar)]Ti(CH3)2 (Ar = 2,6-i-Pr2C6H3) with either elemental Se or the tellurium atom source Te=PBu3 resulted in the formation of bis-µ-chalcogenido dimers [(Ar)NCH2CH2CH2N(Ar)]2Ti(µ-E)2 (E = Se, 2; Te, 3) with concommitant loss of EMe2. The dimers 2 and 3 were characterized spectroscopically and via X-ray crystallography. The two compounds are isostructural in the solid state. The tellurido dimer 3 may also be synthesized by reduction of the diamido dichloride [(Ar)NCH2CH2CH2N(Ar)]2TiCl2 with Na–Hg amalgam followed by treatment with Te=PBu3. This dimer is unreactive toward further Te=PBu3 or stannanes such as HSnBu3. Unlike decamethyltitanocene derivatives, the diamido complex is not an effective catalyst precursor for the heterohydrodecoupling of Te=PBu3 and HSnBu3.Key words: diamido titanium complexes, selenides, tellurides.

scholarly journals CAAC Boranes. Synthesis and characterization of cyclic (alkyl) (amino) carbene borane complexes from BF3 and BH3

2010 ◽  
Vol 6 ◽  
pp. 709-712 ◽  
Author(s):  
Julien Monot ◽  
Louis Fensterbank ◽  
Max Malacria ◽  
Emmanuel Lacôte ◽  
Steven J Geib ◽  
...  
Keyword(s):  
Silica Gel ◽  
Synthesis And Characterization ◽  
Gel Chromatography ◽  
Nmr Analysis ◽  
X Ray ◽  
X Ray Crystallography ◽  
In Situ Formation ◽  
Silica Gel Chromatography

In situ formation of two cyclic (alkyl) (amino) carbenes (CAACs) followed by addition of BF3•Et2O provided the first two examples of CAAC–BF3 complexes: 1-(2,6-diisopropylphenyl)-3,5,5-trimethyl-3-phenylpyrrolidin-2-ylidene trifluoroborane, and 2-(2,6-diisopropylphenyl)-3,3-dimethyl-2-azaspiro[4.5]decan-1-ylidene trifluoroborane. These CAAC–BF3 complexes are robust compounds that are stable to ambient laboratory conditions and silica gel chromatography. They were characterized by spectroscopy and X-ray crystallography. In contrast, a CAAC complex with borane (BH3) was readily formed in situ according to 1H and 11B NMR analysis, but did not survive the workup conditions. These results set the stage for further studies of the chemistry of CAAC boranes.

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