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14 Jan 22:40

The Chemistry of the Cyaphide Ion

by Tim Görlich, Peter Coburger, Eric Yang, Jose Goicoechea, Hansjörg Grützmacher, Christian Müller
The Chemistry of the Cyaphide Ion

128 years after the erroneously assumed synthesis of sodium cyaphide, Na(CP), and 51 years after the definitive proof of the existence of HCP, the chemistry of the cyaphide anion has finally gained momentum. This review summarizes the chemistry of the cyaphide anion, (C≡P), from its beginnings to the state-of-the art.


Abstract

We review the known chemistry of the cyaphide ion, (C≡P). This remarkable diatomic anion has been the subject of study since the late nineteenth century, however its isolation and characterization eluded chemists for almost a hundred years. In this mini-review, we explore the pioneering synthetic experiments that first allowed for its isolation, as well as more recent developments demonstrating that cyaphide transfer is viable in well-established salt-metathesis protocols. The physical properties of the cyaphide ion are also explored in depth, allowing us to compare and contrast the chemistry of this ion with that of its lighter congener cyanide (an archetypal strong field ligand and important organic functional group). Recent studies show that the cyaphide ion has the potential to be used as a versatile chemical regent for the synthesis of novel molecules and materials, hinting at many interesting future avenues of investigation.

31 Oct 14:50

Light‐Induced Divergent Cyanation of Alkynes Enabled by Phosphorus Radicals

by Yanyan Zhang, Yunhong Han, Shengqing Zhu, Feng-Ling Qing, Xiao-Song Xue, Lingling Chu
Light-Induced Divergent Cyanation of Alkynes Enabled by Phosphorus Radicals

A photochemically induced selective and divergent cyanation reaction of alkynes, enabled by phosphorus radicals, is described. With the use of simple triarylphosphine as a co-catalyst, three cyanation reactions, including di-hydrocyanation, anti-Markovnikov hydrocyanation, and domino hydrocyanation/reduction, can be divergently achieved, furnishing a wide array of alkyl dinitriles, alkenyl nitriles, and alkyl nitriles under mild conditions.


Abstract

A photochemically induced selective and divergent cyanation reaction of alkynes, enabled by phosphorus radicals, is described. With the use of simple triarylphosphine as a co-catalyst, three cyanation reactions, including di-hydrocyanation, anti-Markovnikov hydrocyanation, and domino hydrocyanation/reduction, can be divergently achieved, furnishing a wide array of alkyl dinitriles, alkenyl nitriles, and alkyl nitriles under mild conditions. Terminal and internal alkynes are applicable with high efficiency and excellent selectivity. Synthetic applications for biologically active agents and preliminary experimental and computational mechanistic studies are reported.

07 Nov 17:18

4‐Methyltetrahydropyran (4‐MeTHP): Application as an Organic Reaction Solvent

by Shoji Kobayashi, Tomoki Tamura, Saki Yoshimoto, Takashi Kawakami, Araki Masuyama
Chemistry – An Asian Journal 4‐Methyltetrahydropyran (4‐MeTHP): Application as an Organic Reaction Solvent

Organic pastures greener: A comprehensive study on the performance of 4‐methyltetrahydropyran (4‐MeTHP) as a reaction solvent is described. The broad applications and higher stability under free‐radical conditions make this solvent a promising alternative to common organic solvents. This study provides key data for process chemists in choosing a reaction solvent under green chemistry perspectives.


Abstract

4‐Methyltetrahydropyran (4‐MeTHP) is a hydrophobic cyclic ether with potential for industrial applications. We herein report, for the first time, a comprehensive study on the performance of 4‐MeTHP as an organic reaction solvent. Its broad application to organic reactions includes radical, Grignard, Wittig, organometallic, halogen‐metal exchange, reduction, oxidation, epoxidation, amidation, esterification, metathesis, and other miscellaneous organic reactions. This breadth suggests 4‐MeTHP can serve as a substitute for conventional ethers and harmful halogenated solvents. However, 4‐MeTHP was found incompatible with strong Lewis acids, and the C−O bond was readily cleaved by treatment with BBr3. Moreover, the radical‐based degradation pathways of 4‐MeTHP, THP and 2‐MeTHF were elucidated on the basis of GC‐MS analyses. The data reported herein is anticipated to be useful for a broad range of synthetic chemists, especially industrial process chemists, when selecting the reaction solvent with green chemistry perspectives.

25 Apr 07:05

Cyaphide–alkynyl complexes: metal–ligand conjugation and the influence of remote substituents

Dalton Trans., 2019, 48,8131-8143
DOI: 10.1039/C9DT01071H, Paper
Samantha K. Furfari, Matthew C. Leech, Nicola Trathen, Madeleine C. Levis, Ian R. Crossley
A series of cyaphide–alkynyl complexes exhibits significant cooperativity between the electron accepting “–CP” ligand and remote alkynyl substituents, indicative of long-range communication.
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26 Mar 10:21

Decarboxylation with Carbon Monoxide: The Direct Conversion of Carboxylic Acids into Potent Acid Triflate Electrophiles

by R. Garrison Kinney, Bruce A. Arndtsen
Angewandte Chemie International Edition Decarboxylation with Carbon Monoxide: The Direct Conversion of Carboxylic Acids into Potent Acid Triflate Electrophiles

A new route to transform carboxylic acids directly into potent acyl triflate electrophiles is reported. This transformation exploits oxidative carbonylation of carboxylic acids with I2, and is postulated to involve the interception of the Hunsdiecker reaction with CO. Coupling this chemistry with arene trapping offers a mild, room‐temperature approach to generate ketones from carboxylic acids using available reagents, and with only CO2 and salts as byproducts.


Abstract

We report a new strategy for the conversion of carboxylic acids into potent acid triflate electrophiles. The reaction involves oxidative carbonylation of carboxylic acids with I2 in the presence of AgOTf, and is postulated to proceed via acyl hypoiodites that react with CO to form acid triflates. Coupling this chemistry with subsequent trapping with arenes offers a mild, room temperature approach to generate ketones directly from broadly available carboxylic acids without the use of corrosive and reactive Lewis or Bronsted acid additives, and instead from compounds that are readily available, stable, and functional group compatible.

09 Aug 21:29

Tertiary phosphine oxide complexes of lanthanide diiodides and dibromides

Publication date: 1 November 2018

Source: Polyhedron, Volume 154

Author(s): Robert D. Bannister, William Levason, Mark E. Light, Gillian Reid

Abstract

The reaction of OPR3 (R = Me, Ph) with YbI2, EuI2 and EuBr2 in rigorously anhydrous MeCN under N2 produces the divalent lanthanide complexes [LnX2(OPR3)4] (Ln = Yb, Eu, X = I; Ln = Eu, X = Br) in moderate to good yield, whilst [SmI2(OPR3)4] were obtained from SmI2 and OPR3 in dry, degassed thf. These are the first examples involving divalent lanthanide ions and the complexes have been characterised by microanalysis, IR, UV–Vis and 31P{1H} NMR spectroscopy. The X-ray crystal structure of [EuI2(OPPh3)4]·MeCN confirmed the six-coordinate Eu(II) species with a cis-octahedral geometry, which IR spectroscopy suggests is present in all of the OPPh3 complexes. In contrast the [LnX2(OPMe3)4] complexes appear to be trans isomers. The OPPh3 complexes are readily oxidised by dry O2 or I2, yielding the corresponding trivalent cations, [LnX2(OPPh3)4]+; a crystal structure of the product formed by oxidation of [EuI2(OPPh3)4] in MeCN solution confirms this to be [EuI2(OPPh3)4]I3·1.5MeCN, containing a trans-octahedral cation.

Graphical abstract

The first examples of tertiary phosphine oxide complexes of divalent lanthanides are reported, along with spectroscopic and structural data.

Graphical abstract for this article

02 Aug 07:52

Coordination of a stibine oxide to a Lewis acidic stiborane at the upper rim of the biphenylene backbone

Dalton Trans., 2018, 47,12075-12078
DOI: 10.1039/C8DT02872A, Communication
Chang-Hong Chen, François P. Gabbaï
The biphenylene backbone is used to support a stibine oxide stabilized intramolecularly by a SbO → Sb(V) donor–acceptor interaction.
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18 Jun 22:16

[ASAP] Trialkylstibine Complexes of Boron, Aluminum, Gallium, and Indium Trihalides: Synthesis, Properties, and Bonding

by Victoria K. Greenacre, William Levason, Gillian Reid

TOC Graphic

Organometallics
DOI: 10.1021/acs.organomet.8b00265
28 Feb 15:17

Through-conjugation of two phosphaalkyne ('C[triple bond, length as m-dash]P') moieties mediated by a bimetallic scaffold

Dalton Trans., 2018, 47,4428-4432
DOI: 10.1039/C8DT00110C, Communication
Open Access Open Access
Creative Commons Licence&nbsp This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Matthew. C. Leech, Ian R. Crossley
The bis-cyaphide complex [{Ru(dppe)2}2{[small mu ]-(C[triple bond, length as m-dash]C)2C6H4-p}(C[triple bond, length as m-dash]P)2] is the first molecule to incorporate two phosphaalkyne 'C[triple bond, length as m-dash]P' moieties within a through-conjugated scaffold, and demonstrates interesting redox behaviour.
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21 Feb 13:20

Visible-light and thermal driven double hydrophosphination of terminal alkynes using a commercially available iron compound

Chem. Commun., 2018, 54,2774-2776
DOI: 10.1039/C8CC00847G, Communication
Brandon J. Ackley, Justin K. Pagano, Rory Waterman
An air-stable, commercially available iron catalyst provides fast efficient double hydrophosphination of alkynes under thermal or photochemical conditions.
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23 Dec 12:22

Electronic versus steric effects of pyridinophane ligands on Pd(III) complexes

Dalton Trans., 2018, 47,1151-1158
DOI: 10.1039/C7DT04366J, Paper
Fengzhi Tang, Sungho V. Park, Nigam P. Rath, Liviu M. Mirica
Reported herein is the study of the electronic and steric effects of pyridinophane ligands on the corresponding Pd(III) complexes.
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01 Dec 08:51

Evidence for Iron-Catalyzed α-Phosphinidene Elimination with Phenylphosphine

by Justin K Pagano, Brandon J Ackley, Rory Waterman

Abstract

The ubiquitous half-sandwich iron complex [CpFe(CO)2Me] (Cp=η5-C5H5) appears to be a catalyst for α-phosphinidene elimination from primary phosphines. Dehydrocoupling reactions provided initial insight into this unusual reaction mechanism, and trapping reactions with organic substrates gave products consistent with an α elimination mechanism, including a rare example of a three-component reaction. The substrate scope of this reaction is consistent with generation of a triplet phosphinidene. In all, this study presents catalytic phosphinidene transfer to unsaturated organic substrates.

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A simple iron compound can catalytically transfer a phosphinidene equivalent to a 2,3-dimethyl-1,3-butadiene, alkynes, and diethyl disulfide with loss of hydrogen. These phosphinidene transfer reactions and dehydrocoupling catalysis indicate α-phosphinidene elimination (see scheme).

27 Nov 16:48

Systematics of boron halide complexes with dichalcogenoether ligands – Synthesis, structures and reaction chemistry

Publication date: 1 January 2018
Source:Journal of Organometallic Chemistry, Volume 854
Author(s): Coco K.Y.A. Okio, William Levason, Francesco M. Monzittu, Gillian Reid
The complexes [BX3(μ-L−L)BX3] (X = Cl, Br, I; L−L = EtS(CH2)2SEt, MeSe(CH2)2SeMe), [BX′3{o-C6H4(SMe)2}] (X’ = Cl, I), [(BBr3)2{o-C6H4(SMe)2}], [(BBr3)2{o-C6H4(SeMe)2}] and [BI3{o-C6H4(SeMe)2}] have been prepared as moisture-sensitive pale solids by reaction of the appropriate BX3 with the dichalcogenoether in anhydrous n-hexane solution, and characterised by microanalysis, IR and multinuclear (1H, 11B, 77Se{1H}) NMR spectroscopy. In contrast, the [BF3(μ-L−L)BF3], [(BF3)2{o-C6H4(SMe)2}] and [(BF3)2{o-C6H4(SeMe)2}], made from BF3 and the neat ligands, are viscous oils which have a significant vapour pressure of BF3 at ambient temperatures. X-ray crystal structures are reported for [BX3{μ-EtS(CH2)2SEt}BX3] (X = Cl, Br, I), [BBr3{μ-MeSe(CH2)2SeMe}BBr3], [BCl3{o-C6H4(SMe)2}] and [(BBr3)2{μ-o-C6H4(SeMe)2}]. The complexes [(BX3)2{MeTe(CH2)3TeMe}] (X = F, Cl, Br) have been identified in solution by multinuclear NMR spectroscopy, but decompose rapidly, whilst o-C6H4(TeMe)2 decomposes immediately on contact with BBr3 or BCl3. Dealkylation of some of the chalcogenoether ligands at room temperature by BI3, to yield complexes including [BI2{o-C6H4S(SMe)] and [BI2{o-C6H4Se(SeMe)], has been identified and the X-ray structure of [BI2{o-C6H4Se(SeMe)] determined. The trends in behaviour along the series of boron halides and with the various chalcogenoethers are described and compared with the behaviour of BX3 with neutral phosphorus and arsenic donor ligands (Burt et al., Inorg. Chem., 2016, 55, 8852) and with [BX3(EMe2)] (E = S, Se, Te) (Okio et al., J. Organometal. Chem., 2017, 848, 232).

Graphical abstract

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25 Oct 14:35

C-H and H-H activation at a di-titanium centre

Chem. Commun., 2017, 53,13117-13120
DOI: 10.1039/C7CC07726B, Communication
Nikolaos Tsoureas, Jennifer C. Green, F. Geoffrey N. Cloke
An NHC promotes intramolecular C-H activation in bis(pentalene)dititanium; this process is reversed by the addition of hydrogen, forming a dihydride.
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19 Oct 19:56

Metal–Silicon Triple Bonds: Access to [Si(η5-C5Me5)]+ from SiX2(NHC) and its Conversion to the Silylidyne Complex [TpMe(CO)2MoSi(η3-C5Me5)] (TpMe = κ3-N,N′,N″-hydridotris(3,5-dimethyl-1-pyrazolyl)borate)

by Priyabrata Ghana, Marius I. Arz, Gregor Schnakenburg, Martin Straßmann and Alexander C. Filippou

TOC Graphic

Organometallics
DOI: 10.1021/acs.organomet.7b00665
16 Oct 16:36

Synthesis, characterization and theoretical investigations of molybdenum carbonyl complexes with phosphorus/nitrogen/phosphorus ligand as bidentate and tridentate modes

Publication date: 14 December 2017
Source:Polyhedron, Volume 138
Author(s): Seyma Goren Keskin, Julie M. Stanley, Alan H. Cowley
Carbonyl complexes of molybdenum with the phosphorus/nitrogen/phosphorus ligand, PNP-Mo(CO) n , where n = 3, 4 and PNP is N,N-bis[2-(diphenylphosphino)ethyl]phenylamine have been synthesized and characterized by 1H, 31P{1H} NMR, IR (ATR and solution state), Raman, X-ray diffraction, MS and elemental analysis. DFT calculations of the complexes were also performed. The PNP-Mo(CO)4 complex in which the binding mode is bidentate cis-phosphine and, facial and meridional isomers of PNP-Mo(CO)3 in which the binding mode is tridentate were obtained. The facial isomer and the tetracarbonyl complexes were successfully synthesized and purified; however, it was not possible to isolate the meridional isomer. Only a few crystals of the meridional isomer were detected and used for X-ray analysis. When the facial isomer was dissolved in CH2Cl2 or in THF, it was found to undergo decomposition thereby generating the tetracarbonyl complex, meridional isomer, Mo(0) as a dark precipitate along with some facial isomer that was left intact in solution. The reason that the facial isomer was the preferred structure with respect to the meridional isomer was also investigated.

Graphical abstract

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14 Aug 21:08

X-ray characterization of triphenylphosphine-gold(I) olefin π-complexes and the revision of their stability in solution

Publication date: 15 October 2017
Source:Journal of Organometallic Chemistry, Volume 848
Author(s): Petr Motloch, Jan Blahut, Ivana Císařová, Jana Roithová
A large number of cationic Au(I) π-complexes have been reported in the literature. However, a single X-ray structure of genuine [Au(PPh3)(hydrocarbon)]+ π-complex without any additional stabilization has not been published so far. We present herein isolation and X-ray characterization of several complexes of this type. Also, we show that these π-complexes are more stable than previously reported and we investigate different modes of activation of the [Au(PPh3)]Cl precatalyst on their stability in solution.

Graphical abstract

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09 Aug 14:47

[AlCl3(BnMe2-tacn)] - a new metal chelate scaffold for radiofluorination by Cl/F exchange

Dalton Trans., 2017, 46,14519-14522
DOI: 10.1039/C7DT02122D, Communication
William Levason, Sajinder K. Luthra, Graeme McRobbie, Francesco M. Monzittu, Gillian Reid
Radiofluorination of [AlCl3(BnMe2-tacn)] via a Cl/F exchange reaction is described, along with a cartridge-based purification method; the [Al18F19F2(BnMe2-tacn)] exhibits excellent stability (>99% RCP after 3 h).
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21 Jul 08:05

An N-Tethered Uranium(III) Arene Complex and the Synthesis of an Unsupported U–Fe Bond

by Skye Fortier, J. Rolando Aguilar-Calderón, Bess Vlaisavljevich, Alejandro J. Metta-Magaña, Alan G. Goos and Cristian E. Botez

TOC Graphic

Organometallics
DOI: 10.1021/acs.organomet.7b00429
13 Jul 06:52

07/12/17 PHD comic: 'The Conference Morning Session'

Piled Higher & Deeper by Jorge Cham
www.phdcomics.com
Click on the title below to read the comic
title: "The Conference Morning Session" - originally published 7/12/2017

For the latest news in PHD Comics, CLICK HERE!

23 Jun 19:45

Making Use of the Functional Group Combination of a Phosphane/Borane Lewis Pair Connected by an Unsaturated Four-Carbon Bridge

by Gerhard Erker, Guo-Qiang Chen, Constantin G. Daniliuc, Gerald Kehr

Unsaturated, C4-bridged, tBu2P/B(C6F5)2-containing phosphane/borane Lewis pair 6a reacts with 2-methylbutenyne in a two-step reaction sequence of allylboration followed by addition of the P/B frustrated Lewis pair (FLP) to the resulting vinyl group to give the zwitterionic heterobicyclic product 14. The P/B pair 6b (–PMes2) reacts with the conjugated ynone 15 in a similar way by means of allyl-B transfer to the ketone to eventually give the bicycle 17. Compound 6b undergoes 1,4-P/B FLP addition to methyl vinyl ketone, and it adds to an imine or a nitrile by B-allyl transfer. Compound 6a reacts with the persistent TEMPO radical by addition to the boron Lewis acid followed by H-atom transfer from the allylic substituent to nitrogen. The reaction sequence is closed by H abstraction by a second equivalent of TEMPO to yield the tBu2P-CH2-substituted dienyl-B(C6F5)2-OTMP(H) product 34.

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Unsaturated C4-bridged phosphane/borane pairs undergo specific reactions with an enyne and with the persistent TEMPO radical.

19 Jun 15:19

Synthesis, structure and dispersion interactions in bis(1,8-naphthalendiyl)distibine

Dalton Trans., 2017, 46,9227-9234
DOI: 10.1039/C7DT02165H, Paper
C. Ganesamoorthy, S. Heimann, S. Holscher, R. Haack, C. Wolper, G. Jansen, S. Schulz
Naph2Sb21 shows intermolecular interactions in the solid state. Quantum chemical calculations of 1 and the lighter (P, As) and heavier (Bi) congeners showed that intermolecular E[three dots, centered]E interactions (E = P, As, Sb, Bi) are dispersion dominated, while E[three dots, centered][small pi] interactions additionally contained a significant electrostatic contribution.
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23 May 21:02

A Structurally Characterized Fluoroalkyne

by Lewis M. Hall, David P. Tew, Natalie E. Pridmore, Adrian C. Whitwood, Jason M. Lynam, John M. Slattery

Abstract

The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M−C≡CF, is reported. Reaction of [Ru(C≡CH)(η5-C5Me5)(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η5-C5Me5)(dppe)][N(SO2Ph)2]. Subsequent deprotonation with LiN(SiMe3)2 affords the fluoroalkynyl complex [Ru(C≡CF)(η5-C5Me5)(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF2)(η5-C5Me5)(dppe)][N(SO2Ph)2].

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Fancy a fluorine? In contrast to other fluorinated alkynes, structurally characterized {M−C≡CF} exhibits considerable long-term stability. Structural, spectroscopic and computational analyses reveal that this longevity is underpinned by kinetic stabilization by a half-sandwich ruthenium substituent. Subsequent fluorination provides facile access to a rare example of a difluorovinylidene complex.

16 May 09:36

Syntheses and molecular structures of trans-bis(alkynyl) tetrakis-triethylphosphite ruthenium complexes

Publication date: Available online 29 April 2017
Source:Journal of Organometallic Chemistry
Author(s): Samantha G. Eaves, Brian W. Skelton, Paul J. Low
A simple synthesis of complexes trans-[Ru(C≡CC6H4-4-R)2{P(OEt)3}4] from trans-[RuCl2{P(OEt)3}4] and the terminal alkyne is described. Crystallographically determined molecular structures indicate a range of conformers, with the ethynyl arylene rings differing in their orientation with respect to each other across the Ru{P(OEt)3}4 fragment. Electrochemical analysis reveals a well-behaved one-electron oxidation process, which is only some 100 mV more positive that the analogous trans-[Ru(C≡CC6H4-4-R)2(dppe)2] complexes. Quantum chemical calculations reveal largely delocalised electronic structures and suggest that these compounds may find use as wire-like molecules within single molecule electronics.

Graphical abstract

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12 May 10:29

Synthesis, Structure, and Reactivity of Ga-Substituted Distibenes and Sb-Analogues of Bicyclo[1.1.0]butane

by Lars Tuscher, Christoph Helling, Chelladurai Ganesamoorthy, Julia Krüger, Christoph Wölper, Walter Frank, Anton Nizovtsev, Stephan Schulz

Abstract

Monovalent gallanediyl LGa {L=HC[C(Me)N(2,6-iPr2C6H3)]2} reacts with SbX3 to form the Ga-substituted distibenes [(LGaX)2Sb2] (X=NMeEt 1, Cl 2). Upon heating, 2 reacts to the bicyclo[1.1.0]butane analogue [(LGaCl)2(μ,η1:1-Sb4)] 3 containing a [Sb4]2− dianion. Moreover, 2 reacts with Li amides LiNR2 in salt elimination reactions that form the corresponding amido-substituted compounds 1 and [(LGaNMe2)2Sb2] 4, whereas reactions of 4 and [(LGaNMe2)2(μ,η1:1-Sb4)] 5 with two equivalents of GaCl3 resulted in the formation of 2 and 3, respectively. 1, 2 and 3 were characterized by 1H and 13C NMR spectroscopy, elemental analysis, and single crystal X-ray diffraction. In addition, their bonding situation was analyzed by quantum chemical calculations.

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Gallium-antimony compounds: LGa reacts with SbX3 to form Ga-substituted distibenes [(LGaX)2Sb2] (NMeEt 1, Cl 2, NMe2 4). Compounds 2 and 4 were thermally converted into the corresponding tetrastibines [(LGaX)2(μ,η1:1-Sb4)] (Cl 3, NMe2 5). Salt elimination reactions of 2 with Li amides yielded amido-substituted compounds 1 and 4, whereas amide/chloride exchange reactions of 4 and 5 with GaCl3 yielded 2 and 3. Quantum chemical calculations revealed the bonding situation within the complexes.

12 Apr 08:47

Cu(II) Coordination Polymers as Vehicles in the A3 Coupling

by Edward Loukopoulos, Michael Kallitsakis, Nikolaos Tsoureas, Alaa Abdul-Sada, Nicholas F. Chilton, Ioannis N. Lykakis and George E. Kostakis

TOC Graphic

Inorganic Chemistry
DOI: 10.1021/acs.inorgchem.6b03084
29 Mar 20:09

Synthesis of the Highly Reduced [Fe6C(CO)15]4– Carbonyl Carbide Cluster and Its Reactions with H+ and [Au(PPh3)]+

by Marco Bortoluzzi, Iacopo Ciabatti, Cristiana Cesari, Cristina Femoni, Maria Carmela Iapalucci, Stefano Zacchini

The reduction of [Fe6C(CO)16]2– (1) with NaOH in DMSO or with Na/naphthalene in THF affords the highly reduced [Fe6C(CO)15]4– (2) monocarbide tetraanion. The molecular structure of 2 has been crystallographically determined as its [Et4N]4[Fe6C(CO)15]·CH3CN salt, revealing an octahedral structure as expected for a hexanuclear cluster possessing 86 valence electrons. The stepwise protonation of 2 with strong acids such as HBF4·Et2O results first in the monohydride trianion [HFe6C(CO)15]3– (3) and then the purported dihydride dianion [H2Fe6C(CO)15]2– (4), as indicated by 1H NMR spectroscopy. Both 3 and 4 are not stable enough to be isolated and rapidly decompose, yielding the parent dianion 1. The reaction of 2 with a slight excess of Au(PPh3)Cl affords the aurated dianion [Fe6C(CO)15(AuPPh3)2]2– (5), which has been isolated and structurally characterized as its [Et4N]2[Fe6C(CO)15(AuPPh3)2]·2CH3CN salt. DFT calculations allowed us to study, from a computational point of view, the electronic features of the new compounds and possible reaction intermediates.

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The reduction of [Fe6C(CO)16]2– afforded a highly reduced [Fe6C(CO)15]4– cluster, which promptly reacts with H+ and [AuPPh3]+ acids. Structural, spectroscopic, and computational investigations at the DFT level were carried out.

23 Mar 17:07

Synthesis and Properties of Triarylhalostibonium Cations

by Mengxi Yang and François P. Gabbaï

TOC Graphic

Inorganic Chemistry
DOI: 10.1021/acs.inorgchem.7b00293