32475-60-8Relevant academic research and scientific papers
Zerovalent Nickel Compounds Supported by 1,2-Bis(diphenylphosphino)benzene: Synthesis, Structures, and Catalytic Properties
Neary, Michelle C.,Quinlivan, Patrick J.,Parkin, Gerard
, p. 374 - 391 (2018/01/10)
Zerovalent nickel compounds which feature 1,2-bis(diphenylphosphino)benzene (dppbz) were obtained via the reactivity of dppbz towards Ni(PMe3)4, which affords sequentially (dppbz)Ni(PMe3)2 and Ni(dppbz)2. Furthermore, the carbonyl derivatives (dppbz)Ni(PMe3)(CO) and (dppbz)Ni(CO)2 may be obtained via the reaction of CO with (dppbz)Ni(PMe3)2. Other methods for the synthesis of these carbonyl compounds include (i) the formation of (dppbz)Ni(CO)2 by the reaction of Ni(PPh3)2(CO)2 with dppbz and (ii) the formation of (dppbz)Ni(PMe3)(CO) by the reaction of (dppbz)Ni(CO)2 with PMe3. Comparison of the ν(CO) IR spectroscopic data for (dppbz)Ni(CO)2 with other (diphosphine)Ni(CO)2 compounds provides a means to evaluate the electronic nature of dppbz. Specifically, comparison with (dppe)Ni(CO)2 indicates that the o-phenylene linker creates a slightly less electron donating ligand than does an ethylene linker. The steric impact of the dppbz ligand in relation to other diphosphine ligands has also been evaluated in terms of its buried volume (%Vbur) and steric maps. The nickel center of (dppbz)Ni(PMe3)2 may be protonated by formic acid at room temperature to afford [(dppbz)Ni(PMe3)2H]+, but at elevated temperatures, effects catalytic release of H2 from formic acid. Analogous studies with Ni(dppbz)2 and Ni(PMe3)4 indicate that the ability to protonate the nickel centers in these compounds increases in the sequence Ni(dppbz)2 3)2 3)4; correspondingly, the pKa values of the protonated derivatives increase in the sequence [Ni(dppbz)2H]+ 3)2H]+ 3)4H]+. (dppbz)Ni(PMe3)2 and Ni(PMe3)4 also serve as catalysts for the formation of alkoxysilanes by (i) hydrosilylation of PhCHO by PhSiH3 and Ph2SiH2 and (ii) dehydrocoupling of PhCH2OH with PhSiH3 and Ph2SiH2.
Reactivity of Nickel(II) Diphosphine Complexes towards Alkoxides: a New Route to the Synthesis of Nickel(0) Compounds through Nickel(II) Alkoxides
Sacco, Adriano,Mastrorilli, Pietro
, p. 2761 - 2764 (2007/10/02)
Reaction of with NaOR (R = Me, Et or i-Pr) under a dinitrogen atmosphere afforded , Ni(OR)2 and aldehyde (or acetone when R = Pri) in 1:1:1 ratio, showing the peculiar reducing effect of alkoxide promoted by the chelating property of the phosphorus ligand.The reaction of NaOMe with afforded mainly when carried out in the absence of free diphosphine, and in the presence of free diphosphine.The reaction always yields the nickel(0) species when it is carried out under a carbon monoxide atmosphere.The intermediate formation of unstable alkoxo(diphosphine)nickel(II) complexes has been demonstrated by recording the 31P NMR spectra of the reactiong solutions at low temperature; in the case of the reaction of with NaOMe only, it was possible to isolate as a solid the complex, which has been fully characterized by analytical and spectroscopic (IR and 1H, 31P NMR) methods.A possible route by which nickel(0) complexes could be formed is discussed.
Insertion of Carbon Monoxide into Nickel-Alkyl Bonds of Monoalkyl- and Dialkylnickel(II) Complexes, NiR(Y)L2 and NiR2L2. Preparation of Ni(COR)(Y)L2 from NiR(Y)L2 and Selective Formation of Ketone, Diketone, and Aldehyde from NiR2L2
Yamamoto, Takakazu,Kohara, Teiji,Yamamoto, Akio
, p. 2161 - 2168 (2007/10/02)
Reactions of monoalkylnickel(II) complexes, NiR(Y)L2 (R=CH3, C2H5; Y=Cl, suc(succinimido), pht(phthalimido), OC6H4-p-CN; L=1/2 bpy (2,2'-bipyridine), PEt3 (triethylphosphine)), with CO afford monoacylnickel(II) complexes, Ni(COR)(Y)L2, which are characterized by elemental analysis and spectroscopies (IR and NMR).Reactions of the acylnickel(II) complexes with alcohols and aniline give the corresponding esters and amides, respectively.Exposure of Ni(COR)(Y)L2 to dry air leads to oxidation of RCO to a RCOO ligand giving a complex formulated as NI(OCOR)(Y)L2.Reactions of dimethylnickel(II) complexes, Ni(CH3)2L2 (L=1/2 bpy, PEt3, 1/2dpe (1,2-bis(diphenylphosphino)ethane, 1/2 dpp (1,3-bis(diphenylphosphino)propane), with carbon monoxide afford acetone and/or 2,3-butanedione in medium to high yields, the acetone/2,3-butanedione ratio varying with the ligand L, reaction temperature, and additives such as maleic anhydride and triphenylphosphine.Generally the acetone/2,3-butanedione ratio decreases with increase in thermal stabilities of Ni(CH3)2L2.Ni(C2H5)2(bpy) and Ni(n-C3H7)2(bpy) give 3-pentanone and 4-heptanone, respectively, on treating them with CO, whereas Ni(C2H5)2(dpe) produces C2H5CHO and C2H4.
Approximate force constants for tetrahedral metal carbonyls and nitrosyls
Van Hecke, Gerald R.,Horrocks Jr., William DeW.
, p. 1960 - 1968 (2008/10/08)
Approximate carbonyl and nitrosyl force constants have been calculated for the molecules in the tetrahedral isoelectronic series Mn(NO)3(CO), Fe(NO)2(CO)2, Co(NO)(CO)3, Ni(CO)4, and their substituted derivatives. The required secular equations are given for species having two different oscillators. These force constants provide a quantitative means for comparing relative π-acceptor strengths of the substituent ligands. Explicit inclusion of the CN oscillator of isonitriles is shown to be important in derivatives of ligands of this type. Empirical relationships have been determined which allow the prediction of force constants and frequencies in substituted derivatives provided information on a related molecule is available.
