Synthesis and Characterisation of Two Lithium Tetramethylberyllate Salts and a Series of β-Diketiminato Beryllium Alkyl Complexes

2020 ◽  
Vol 73 (12) ◽  
pp. 1144
Author(s):  
Albert Paparo ◽  
Caspar N. de Bruin-Dickason ◽  
Cameron Jones
Keyword(s):  
Titration Method ◽  
Alkyl Complexes ◽  
Elimination Reactions ◽  
Synthetic Studies ◽  
Alkane Elimination

A safer route than that previously published for the synthesis of [BeI2(OEt2)2] has been developed. Reactions of beryllium dihalide complexes [BeX2(OEt2)2] (X=Br or I) with either LiMe or LiBun lead to mixtures of products, which have been shown to act as sources of ‘BeR2’ (R=Me or Bun) in previous synthetic studies. Here, a titration method has been developed to determine the quantity of metal alkyl residues in these ‘BeR2’ mixtures that are available for subsequent alkane elimination reactions. Treating ‘BeMe2’ mixtures with N,N,N′,N′-tetramethylethylenediamine (tmeda) gave two lithium tetramethylberyllate compounds, [{(tmeda)Li}2(μ-BeMe4)] and [{[(tmeda)Li](BeMe4)(μ-Li)}∞], which were crystallographically characterised. Treatment of insitu-generated ‘BeR2’ solutions with several β-diketimines (HC{C(Me)=NR}{=C(Me)N(H)R}, NacnacH, R=aryl or alkyl) yielded a series of β-diketiminato beryllium alkyl complexes, [(Nacnac)BeR], including the first chiral example of such a compound. Crystallographic studies of these reveal them to be monomeric, with planar three-coordinate beryllium centres.

scholarly journals Ligand influence on intramolecular cyclometalation in bis(phosphinimine) rare earth alkyl complexes

2016 ◽  
Vol 94 (4) ◽  
pp. 330-341 ◽  
Author(s):  
Kevin R.D. Johnson ◽  
Breanne L. Kamenz ◽  
Paul G. Hayes
Keyword(s):  
Rare Earth ◽  
Kinetic Analysis ◽  
Ancillary Ligand ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyl Complexes ◽  
Ortho Metalation ◽  
Elimination Reactions ◽  
Alkane Elimination

The synthesis and reactivity of two new bis(phosphinimine)carbazole ligands (PippN=PMe2)2DMC (HLA, 3) and (PippN=P(C4H8))2DMC (HLB, 10), where Pipp = para-isopropylphenyl and DMC = 3,6-dimethylcarbazole, are reported. Dialkyl lutetium complexes of 3 and 10 were prepared in the presence of DMAP and THF by reaction of the proteo ligands with the new trialkyl reagent, Lu(CH2SiMe3)3(DMAP)2 (4) as well as Lu(CH2SiMe3)3(THF)2. For both ligands 3 and 10, the resulting lutetium complexes were prone to intramolecular cyclometalative alkane elimination reactions whereby the location of cyclometalation was influenced by the identity of the ancillary ligand coordinated to the metal. For ligand 3, cyclometalation of two PMe2 groups generated the complex (LA-κ3N,κ2C)Lu(DMAP)2 (5), whereas ligand 10 resulted in the single ortho-metalation of a para-isopropylphenyl ring to afford (LB-κ3N,κC)Lu(CH2SiMe3) (12). When complexed with scandium, ligand 10 behaved differently; double cyclometalation of two phospholane moieties resulted in the species (LB-κ3N,κ2C)Sc (15). The nature of the cyclometalation reactivity of ligands 3 and 10 is supported by X-ray crystallography and kinetic analysis, respectively.

scholarly journals 1,8-Bis(silylamido)naphthalene complexes of magnesium and zinc synthesised through alkane elimination reactions

2017 ◽  
Vol 46 (12) ◽  
pp. 4101-4110 ◽  
Author(s):  
Mark A. Bradley ◽  
Chris Birchall ◽  
Alexander J. Blake ◽  
William Lewis ◽  
Graeme J. Moxey ◽  
...  
Keyword(s):  
Reaction Conditions ◽  
Coordination Environment ◽  
Elimination Reactions ◽  
Alkane Elimination

Alkane elimination reactions afford magnesium and zinc 1,8-bis(triorganosilyl)diamidonaphthalene complexes, where the tuning of the reaction conditions and steric bulk allows manipulation of the coordination environment.

Rhenium(VII) Oxo−Alkyl Complexes:  Reductive and α-Elimination Reactions

1996 ◽  
Vol 15 (3) ◽  
pp. 1023-1032 ◽  
Author(s):  
Shiang Cai ◽  
David M. Hoffman ◽  
Derk A. Wierda
Keyword(s):  
Alkyl Complexes ◽  
Elimination Reactions

Alkane Elimination Reactions between Yttrium Alkyls and Tungsten Hydrides

2014 ◽  
Vol 2014 (7) ◽  
pp. 1211-1217 ◽  
Author(s):  
Adam P. Sobaczynski ◽  
Johannes Obenauf ◽  
Rhett Kempe
Keyword(s):  
Elimination Reactions ◽  
Alkane Elimination ◽  
And Tungsten

Synthetic studies toward inducamide C

2021 ◽  
Author(s):  
Ardalan A. Nabi ◽  
Lydia M. Scott ◽  
Daniel P. Furkert ◽  
Jonathan Sperry
Keyword(s):  
Natural Product ◽  
Structural Revision ◽  
Synthetic Studies

The rare benzoxazepine ring in the alkaloid inducamide C is unstable and prone to rearrangement, indicating that structural revision of the natural product may be necessary.

Pengaruh Jumlah Pencucian Beras dengan Kadar Klorin

2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto
Keyword(s):  
Mucous Membrane ◽  
Confidence Level ◽  
Iodometric Titration ◽  
Titration Method ◽  
Anova Test ◽  
Average Value ◽  
Significant Difference ◽  
The Difference

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.

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