Transition Metal Complexes of Bis(Trimethyl‐silyl)Amine (1,1,1,3,3,3‐Hexamethyldisilazane)

Bradley, D. C.; Copperthwaite, Richard G.; Extine, M. W.; Reichert, W.; Chisholm, Malcolm H.

doi:10.1002/9780470132494.ch18

Cited by 50 publications

(35 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the product of the 1 : 3 reaction Bradley and coworkers reported that: ‘the dark green product sublimes at 80 °C, 0.005 mmHg with decomposition’ [11] . In contrast for 1 , crystallized from a 2 : 3 reaction a sublimation temperature of 120 °C and 0.005 Torr was reported later on by the same authors [23] . In our case upon increasing the temperature of the oil bath, an almost white (very pale green) sublimate started to form at about 55–60 °C.…”

Section: Synthesis and Structurementioning

confidence: 88%

“…Bradley and coworkers originally reported for the synthesis of 1 a 1 : 3 reaction of FeCl 3 and LiN(SiMe 3 ) 2 in thf [11] . This protocol was later on refined and changed to a 2 : 3 reaction stoichiometry in benzene solution resulting in yields of 62 % [23] . Lee and coworkers again utilized for the synthesis of 1 the reaction of the sodium salt NaN(SiMe 3 ) 2 with 2/3 equivalents of FeCl 3 in benzene as a solvent similar to the approach of Bürger and Wannagat.…”

Section: Synthesis and Structurementioning

confidence: 99%

See 1 more Smart Citation

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties

et al. 2021

View full text Add to dashboard Cite

For the synthesis of the ferric bis(trimethylsilyl)amido complex [Fe{N(SiMe3)2}3] literature gives differing synthetic protocols based on crystallization from solution. In this report we present a ‘solvent‐free’ structural phase of [Fe{N(SiMe3)2}3] which was isolated by sublimation of the product obtained from the reaction of 2 eq FeCl3 with 3 eq LiN(SiMe3)2 in benzene. It could be characterized by single crystal as well as powder XRD and elemental analysis. However, 57Fe Mößbauer spectroscopy suggests a contamination of the main product with an Fe(II) species. Also, a part of the solid reaction byproducts from the reactions in solution were identified by powder XRD and 7Li MAS NMR which indicate distinct redox side reactions between oxidizing FeCl3 and reducing LiN(SiMe3)2, a fact which rationalizes the lower than expected yields and the observation of an Fe(II) impurity compound. AC magnetic measurements of [Fe{N(SiMe3)2}3] have been performed in an extended frequency range up to 104 s−1, allowing for a more precise evaluation of the magnetic relaxation parameters when compared to previously published measurements.

show abstract

Section: Synthesis and Structurementioning

confidence: 88%

Section: Synthesis and Structurementioning

confidence: 99%

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The complex Cr{N(SiMe 3 ) 2 } 3 was synthesised according to the protocol previously reported by Bradley and isolated as a dark green air-/moisture-sensitive solid, which was handled under an inert atmosphere [ 62 ]. Anal .…”

Section: General Experimentalmentioning

confidence: 99%

The Role of Catalyst Support, Diluent and Co-Catalyst in Chromium-Mediated Heterogeneous Ethylene Trimerisation

et al. 2018

View full text Add to dashboard Cite

Sequential treatment of a previously-calcined solid oxide support (i.e. SiO2, γ-Al2O3, or mixed SiO2–Al2O3) with solutions of Cr{N(SiMe3)2}3 (0.71 wt% Cr) and a Lewis acidic alkyl aluminium-based co-catalyst (15 molar equivalents) affords initiator systems active for the oligomerisation and/or polymerisation of ethylene. The influence of the oxide support, calcination temperature, co-catalyst, and reaction diluent on both the productivity and selectivity of the immobilised chromium initiator systems have been investigated, with the best performing combination (SiO2−600, modified methyl aluminoxane-12 {MMAO-12}, heptane) producing a mixture of hexenes (61 wt%; 79% 1-hexene), and polyethylene (16 wt%) with an activity of 2403 g gCr−1 h−1. The observed product distribution is rationalised by two competing processes: trimerisation via a supported metallacycle-based mechanism and polymerisation through a classical Cossee-Arlman chain-growth pathway. This is supported by the indirect observation of two distinct chromium environments at the surface of the oxide support by a solid-state 29Si NMR spectroscopic study of the Cr{N(SiMe3)2}x/SiO2−600 pro-initiator.Electronic supplementary materialThe online version of this article (10.1007/s11244-018-0891-8) contains supplementary material, which is available to authorized users.

show abstract

“…PTF-Fe was synthesized in a three-step reaction, as shown in Scheme 1. In the first step, synthesis of Fe[N(SiMe 3 ) 2 ] 2 was done by reacting FeCl 2 with 2 molar equivalent of LiN(SiMe 3 ) 2 at room temperature in an anhydrous tetrahydrofuran solvent under argon atmosphere followed by purification, similar to the published procedure [24][25][26][27][28][29] . In the second step, a flame-dried three neck flask fitted with a magnetic stirring bar was charged with phloroglucinol (500 mg, 3.96 mmol) and toluene (40 ml) solvent.…”

Section: Synthesis Of Ptf-fe Complexmentioning

confidence: 99%

Hydrogen Storage in a Crosslinked Phloroglucinol-Terephthalaldehyde Framework with Exposed Iron Sites

Pareek¹,

Rohan²,

Cheng³

2017

Res. Rev. J Mat. Sci

View full text Add to dashboard Cite

The rapid consumption of fossil fuels worldwide has escalated greenhouse emission to a unsustainable level and has inspired the global research community to search for alternative energy resources [1]. Hydrogen is an environmentally clean and efficient energy carrier for a wide variety of applications [2]. Unfortunately, lack of safe, high density hydrogen storage methods at near ambient conditions has been deemed to be the bottleneck that prevents broad market acceptance of hydrogen technologies. Technically, hydrogen storage can be realized via chemisorption [3] in the form of chemical hydrides [4] , complex hydrides [3] , or physisorption [1] in porous carbon based materials [5] , zeolites [6] , metal organic frameworks (MOFs) [1,7,8] and porous organic frameworks (POFs) [9-15]. Nevertheless, most of the chemisorptionbased materials exhibit relatively poor kinetics and require an elevated temperature to release the hydrogen gas [3] , while most of the physisorption-based materials show fast adsorption-desorption kinetics but negligible hydrogen storage capacity at ambient temperature due to the weak host-H 2 interaction in the range of 3-7 kJ mol-1 [16]. It has been shown that hydrogen storage capacity in physisorption-based materials can be improved if the associated enthalpy of adsorption is enhanced in the range of 15-20 kJ mol-1 , which is substantially higher than the typical van der Waals force [17]. To enhance H 2 affinity in a host material via physisorption, extensive research efforts have been made to develop materials with coordinatively unsaturated metal sites. The metal elements selected are chiefly from the first row of transition metal series due to their unique capabilities to stabilize the M- 2-H 2 complexes via electron backdonation from metal d-orbitals to the antibonding orbital of H 2 (σ*) and to accommodate several H 2 molecules per each metal atom [18,19]. For example, in a phloroglucinol-terephthalaldehyde based framework with coordinatively unsaturated Cr metals, a high excess hydrogen uptake up to 1.5 wt% at 298 K and 100 atm with an isosteric heat of adsorption (Qst) up to 11.5 kJ mol-1 has been reported recently by our group [18]. Sumida et al. [20] also demonstrated a high Qst of 11.9 kJ mol-1 on coordinatively unsaturated iron metal sites in Fe-BTT MOF (BTT 3-=1,3,5-benzenetristetrazolate). Similar observations have also been made in several recent studies [21,22]. In this work, we report hydrogen storage with a significant capacity in a mesoporous phloroglucinol-terephthalaldehyde framework compound decorated with exposed iron atoms (PTF-Fe) [23] .

show abstract

Transition Metal Complexes of Bis(Trimethyl‐silyl)Amine (1,1,1,3,3,3‐Hexamethyldisilazane)

Cited by 50 publications

References 5 publications

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties

The Role of Catalyst Support, Diluent and Co-Catalyst in Chromium-Mediated Heterogeneous Ethylene Trimerisation

Hydrogen Storage in a Crosslinked Phloroglucinol-Terephthalaldehyde Framework with Exposed Iron Sites

Contact Info

Product

Resources

About

Transition Metal Complexes of Bis(Trimethyl‐silyl)Amine (1,1,1,3,3,3‐Hexamethyldisilazane)

Cited by 50 publications

References 5 publications

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe3)2}3] – Synthesis, Structure and Properties

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe3)2}3] – Synthesis, Structure and Properties

The Role of Catalyst Support, Diluent and Co-Catalyst in Chromium-Mediated Heterogeneous Ethylene Trimerisation

Hydrogen Storage in a Crosslinked Phloroglucinol-Terephthalaldehyde Framework with Exposed Iron Sites

Contact Info

Product

Resources

About

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties

A “Solvent‐Free” Crystal Structure of [Fe{N(SiMe₃)₂}₃] – Synthesis, Structure and Properties