scholarly journals Ring opening polymerisation of L and rac lactide using group 4 permethylpentalene aryloxides and alkoxides

2021 ◽  
Author(s):  
Zoe Turner ◽  
Jessica Lamb ◽  
Thomas Robinson ◽  
Dipa Mandal ◽  
Jean-Charles Buffet ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Ring Opening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
New Family ◽  
Group 4 ◽  
Multinuclear Nmr Spectroscopy

A new family of group 4 permethylpentalene (C8Me62–; Pn*) aryloxide and alkoxide complexes have been synthesised and fully characterised by multinuclear NMR spectroscopy and single-crystal X-ray diffraction; (η8-C8Me6)Zr(OR)2 (R =...

scholarly journals Half-Sandwich Arene-Osmium(II) Complexes with Phosphinite Ligands

Molbank ◽  
10.3390/m1110 ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. M1110 ◽  
Author(s):  
Rebeca González-Fernández ◽  
Javier Borge ◽  
Pascale Crochet ◽  
Victorio Cadierno
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Diffraction Study ◽  
Elemental Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Intramolecular Exchange ◽  
Multinuclear Nmr Spectroscopy ◽  
Half Sandwich

The synthesis of a series of arene-osmium(II) complexes containing phosphinite-type ligands, namely, [OsCl2(η6-p-cymene){R2PO(CH2)nPh}] (R = Ph, n = 1 (4a), 2 (4b), 3 (4c); R = iPr, n = 1 (5a), 2 (5b), 3 (5c)) and [OsCl2(η6-benzene){iPr2PO(CH2)2Ph}] (7), is presented. All these compounds were characterized by elemental analysis and multinuclear NMR spectroscopy (31P{1H}, 1H and 13C{1H}), and the structure of [OsCl2(η6-p-cymene){Ph2PO(CH2)3Ph}] (4c) unequivocally confirmed through a single-crystal X-ray diffraction study. Attempts to generate the tethered species [OsCl2{η6:κ1(P)-C6H5(CH2)nOPR2}] by intramolecular exchange of the coordinated arene in 4-5a-c or 7, upon thermal or MW heating, failed.

Unusual Rearrangement of Naphthalene in the Synthesis of a Novel B8-B8-Bridged Derivative in the [(1,2-C2B9H11)2-3-Co]- Series. X-Ray Structure and 11B NMR Spectra of [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- (CH3)4N+

1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unusual Rearrangement ◽  
Multinuclear Nmr Spectroscopy ◽  
11B Nmr ◽  
Isolated Compound

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.

Dimethyl Sulfate Induced Nucleophilic Substitution of the [Bis(1,2-dicarbollido)-3-cobalt(1-)]ate Ion. Syntheses, Properties and Structures of Its 8,8'-μ-Sulfato, 8-Phenyland 8-Dioxane Derivatives

1997 ◽  
Vol 62 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Jaromír Plešek ◽  
Stanislav Heřmánek ◽  
Andreas Franken ◽  
Ivana Císařová ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Nucleophilic Substitution ◽  
Acid Catalysis ◽  
Dimethyl Sulfate ◽  
General Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Multinuclear Nmr Spectroscopy

Syntheses and structures of [8,8'-μ-(OSO2O)(1,2-C2B9H10)2-3-Co]-and [(8-Ph-1,2-C2B9H10)-3-Co-(1',2'-C2B9H11]- ions and of [(8-dioxane-1,2-C2B9H10)-3-Co-(1',2'-C2B9H11)] zwitterion are described. All compounds result on dimethyl sulfate induced nucleophilic B-substitution of the parent cobalta-carborane sandwich ion under acid catalysis. A general mechanism is proposed. Constitutions of all compounds are inferred from the mass and multinuclear NMR spectroscopy and all structures are established by X-ray diffraction. Selected NMR and X-ray data are presented.

scholarly journals Macrocycles containing 1,1′-ferrocenyldiselenolato ligands on group 4 metallocenes

2018 ◽  
Vol 47 (15) ◽  
pp. 5415-5421 ◽  
Author(s):  
Clara Sanchez-Perez ◽  
Caroline E. Knapp ◽  
Minna M. Karjalainen ◽  
Raija Oilunkaniemi ◽  
Claire J. Carmalt ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Group 4

Macrocyclic [Fe(η5-C5H4Se)2M(η5-C5H4R)2]2 [M = Ti (1), Zr (2), Hf (3), R = H; and M = Zr (4), Hf (5), R = tBu] were prepared and characterized by 77Se NMR spectroscopy and the crystal structures of 1–3 and 5 were determined by single-crystal X-ray diffraction.

Synthesis of Sterically Demanding Bis(phosphinimine) Dibenzofuran Ligands and Subsequent Zinc Metalation

2015 ◽  
Vol 68 (3) ◽  
pp. 373 ◽  
Author(s):  
Matthew T. Zamora ◽  
Saif M. Zahir ◽  
Kevin R. D. Johnson ◽  
Clay J. Barnson ◽  
Craig A. Wheaton ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ambient Temperature ◽  
Elemental Analysis ◽  
Elimination Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Sterically Demanding ◽  
Multinuclear Nmr Spectroscopy ◽  
Alkane Elimination

In light of previous success surrounding the use of bis(phosphinimine)dibenzofuran ligands for zinc-mediated lactide polymerization, a series of sterically demanding P=N pincer compounds have been prepared with important steric and electronic modifications at both P- and N-sites (L, 3a–d). These systems are highly crystalline and have been extensively characterized using multinuclear NMR spectroscopy, elemental analysis, and X-ray diffraction. The ligands can be transformed into their protonated analogues [HL][BArF4] (4a–d, [BArF4] = [B(m-(CF3)2-C6H3)4]) by reaction with Brookhart’s acid, and subsequently coordinated to zinc via an alkane elimination reaction with [ZnEt2] at ambient temperature to afford the corresponding [LZnEt][BArF4] cationic complexes 5a–d. In addition, an unusual chloridozinc species [LZnCl][BArF4] (5c′) has been isolated and structurally characterized, providing comparisons to previously established ligand sets with similar geometries.

Pentafluorophenyl and phenyl substituted azidoborates

2002 ◽  
Vol 80 (11) ◽  
pp. 1444-1450 ◽  
Author(s):  
Wolfgang Fraenk ◽  
Thomas M Klapötke ◽  
Burkhard Krumm ◽  
Heinrich Nöth ◽  
Max Suter ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Boron Atom ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
X Ray Crystallography ◽  
Multinuclear Nmr Spectroscopy

The azidoborates [(C6F5)4–nB(N3)n]– (n = 1–3) (1–3) were synthesized by reacting the corresponding borane with [R]N3 (R = Me4N, Ph4P). To study the influence of the electron withdrawing C6F5-substituent on the boron atom, [Me4N][(C6H5)3BN3] (4) was also prepared. All compounds were fully characterized by IR, Raman, and multinuclear NMR spectroscopy in addition to characterization by single crystal diffraction analyses.Key words: azidoborate, pentafluorophenyl, multinuclear NMR spectroscopy, X-ray crystallography.

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