Просмотр кода страницы Английская Википедия:Dichlorobis(triphenylphosphine)nickel(II)

{{Английская Википедия/Панель перехода}}
{{Chembox
| Name=Dichlorobis(triphenylphosphine){{shy}}nickel(II)
|ImageFile1 = TransNiCl2P2&tetrahedral.png
|ImageSize1 = 300px
|ImageFile2 = Dichlorobis(triphenylphosphine)nickel(II)-isomers-from-xtals-3D-bs-17.png
|ImageSize2 = 300px
|IUPACName = dichloridobis(triphenylphosphane)nickel(II)
|OtherNames = Bis(triphenylphosphine)nickel(II) dichloride<br />Bis(triphenylphosphine)nickel(II) chloride<br />Dichlorobis(triphenylphosphine)nickel(II)<br />Bis(triphenylphosphine)nickel chloride
|Section1 = {{Chembox Identifiers
|CASNo = 39716-73-9
|CASNo_Comment = (tetrahedral form)
|CASNo1 = 14264-16-5
|CASNo1_Comment = (square planar form)
|PubChem = 498315
|ChemSpiderID = 76051
|EC_number = 238-154-8
<!-- | ECHA = 100.034.670 -->
| StdInChI=1S/2C18H15P.2ClH.Ni/c2*1-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18;;;/h2*1-15H;2*1H;/q;;;;+2/p-2
|StdInChIKey = ZBRJXVVKPBZPAN-UHFFFAOYSA-L
|SMILES = C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.C1=CC=C(C=C1)P(C2=CC=CC=C2)C3=CC=CC=C3.Cl[Ni]Cl
}}
|Section2 = {{Chembox Properties
|Formula = C<sub>36</sub>H<sub>30</sub>Cl<sub>2</sub>NiP<sub>2</sub>
|Appearance = purple-blue (tetrahedral) or red (sq. planar)
}}
|Section3 = {{Chembox Hazards
|GHSPictograms = {{GHS07}}{{GHS08}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|302|317|350|412}}
|PPhrases = {{P-phrases|201|202|261|264|270|272|273|280|281|301+312|302+352|308+313|321|330|333+313|363|405|501}}
 }}
}}

'''Dichlorobis(triphenylphosphine)nickel(II)''' refers to a pair of [[metal phosphine complex]]es with the formula NiCl<sub>2</sub>[P(C<sub>6</sub>H<sub>5</sub>)<sub>3</sub>]<sub>2</sub>. The compound exists as two isomers, a paramagnetic dark blue solid and a diamagnetic red solid. These complexes function as [[catalyst]]s for [[organic synthesis]].<ref name="Montgomery Synthesis">Montgomery, J. Science of Synthesis Georg Thiene Verlag KG, Vol. 1, p 11, CODEN: SSCYJ9</ref>

==Synthesis and structure==
The blue isomer is prepared by treating hydrated [[nickel chloride]] with [[triphenylphosphine]] in alcohols or glacial [[acetic acid]]:<ref name="Montgomery Synthesis" />
:NiCl<sub>2</sub>•6H<sub>2</sub>O + 2 PPh<sub>3</sub> → NiCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub> + 6 H<sub>2</sub>O
When allowed to crystallise from chlorinated solvents, the [[tetrahedral]] isomer converts to the square planar isomer.

The [[square planar]] form is red and diamagnetic. The phosphine ligands are [[Cis–trans isomerism#Coordination complexes|trans]] with respective Ni-P and Ni-Cl distances of 2.24 and 2.17 Å.<ref>{{cite journal | last1 = Batsanov | first1 = Andrei S. | last2 = Howard | first2 = Judith A. K. | year = 2001 | title = trans-Dichlorobis(triphenylphosphine)nickel(II) bis(dichloromethane) solvate: redetermination at 120 K | journal = Acta Crystallogr E | volume = 57 | pages = 308–309 | doi = 10.1107/S1600536801008741 | s2cid = 97381117 }}</ref><ref>{{cite journal | last1 = Corain | first1 = B. | last2 = Longato | first2 = B. | last3 = Angeletti | first3 = R. | last4 = Valle | first4 = G. | year = 1985 | title = trans:-[Dichlorobis(triphenylphosphine)nickel(II)]·(C<sub>2</sub>H<sub>4</sub>Cl<sub>2</sub>)<sub>2</sub> a clathrate of the allogon of venanzi's tetrahedral complex | journal = Inorg. Chim. Acta | volume = 104 | pages = 15–18 | doi = 10.1016/S0020-1693(00)83780-9 }}</ref> The blue form is paramagnetic and features tetrahedral Ni(II) centers. In this isomer, the Ni-P and Ni-Cl distances are elongated at 2.32 and 2.21 Å.<ref>{{cite journal | last1 = Garton | first1 = G. | last2 = Henn | first2 = D. E. | last3 = Powell | first3 = H. M. | last4 = Venanzi | first4 = L. M. | title = Tetrahedral nickel(II) complexes and the factors determining their formation. Part V. The tetrahedral co-ordination of nickel in dichlorobistriphenylphosphinenickel | journal = J. Chem. Soc. | year = 1963 | volume = 1963 | pages = 3625–3629 | doi = 10.1039/JR9630003625 }}</ref><ref>{{cite journal | last1 = Brammer | first1 = L. | last2 = Stevens | first2 = E. D. | year = 1989 | title = Structure of dichlorobis(triphenylphosphine)nickel(II) | journal = Acta Crystallogr C | volume = 45 | issue = 3| pages = 400–403 | doi = 10.1107/S0108270188011692}}</ref>

As illustrated by the title complexes, tetrahedral and square planar isomers coexist in solutions of various four-coordinated nickel(II) complexes. Weak field ligands, as judged by the [[spectrochemical series]], favor tetrahedral geometry and strong field ligands favor the square planar isomer. Both weak field (Cl<sup>−</sup>) and strong field (PPh<sub>3</sub>) ligands comprise NiCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>, hence this compound is borderline between the two geometries. [[Steric effect]]s also affect the equilibrium; larger ligands favoring the less crowded tetrahedral geometry.<ref>{{Greenwood&Earnshaw2nd}}</ref>

==Applications==
The complex was first described by [[Walter Reppe]] who popularized its use in [[alkyne trimerisation]]s and [[carbonylation]]s.<ref>{{cite journal | last1 = Reppe | first1 = Walter | last2 = Sweckendiek | first2 = Walter | year = 1948 | title = Cyclisierende Polymerisation von Acetylen. III Benzol, Benzolderivate und hydroaromatische Verbindungen | journal = Joachim Justus Liebigs Annalen der Chemie | volume = 560 | issue = 1| pages = 104–16 | doi = 10.1002/jlac.19485600104 }}</ref> Dichlorobis(triphenylphosphine)nickel(II) is a catalyst in [[Suzuki reaction]]s, although usually inferior in terms of activity.<ref>{{cite journal | doi = 10.1039/c3cs35521g | title = Transition-metal-catalyzed Suzuki–Miyaura cross-coupling reactions: A Remarkable Advance from Palladium to Nickel Catalysts | year = 2013 | last1 = Han | first1 = Fu-She | journal = Chemical Society Reviews | volume = 42 | issue = 12 | pages = 5270–98 | pmid = 23460083}}</ref>

[[File:Ni(PPh3)2Cl2 scheme.tif|center|330x330px|thumb|A [[cross coupling reaction]] mediated by Ni(cod)<sub>2</sub> and Ni(PPh<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>.<ref>{{Cite journal |last1=Johnson |first1=Jeffrey S. |last2=Berman |first2=Ashley M. |date=2005-07-01 |title=Nickel-Catalyzed Electrophilic Amination of Organozinc Halides |journal=Synlett |language=en |volume=2005 |issue=11 |pages=1799–1801 |doi=10.1055/s-2005-871567}}</ref>]]

==See also==
* [[Bis(triphenylphosphine)palladium(II) chloride]]
* [[Bis(triphenylphosphine)platinum(II) chloride]]

==References==
{{reflist}}

[[Category:Nickel complexes]]
[[Category:Triphenylphosphine complexes]]
[[Category:Chloro complexes]]
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