175442-52-1Relevant articles and documents
Magnesium Stung by Nonclassical Scorpionate Ligands: Synthesis and Cone-Angle Calculations
Stuhl, Christoph,Maichle-M?ssmer, C?cilia,Anwander, Reiner
, p. 14254 - 14268 (2018)
A series of tris(pyrazolyl)alkane (RCTp) scorpionate ligands of the type RCTp3-R′ (R=Me, nBu, SiMe3; R′=H, Me, Ph, iPr, tBu) were synthesized and their ability to coordinate methylmagnesium moieties was examined. The reaction of Mg(AlMe4)2 with neutral proligands HCTp3-Ph or Me3SiCTp3-Me, containing a non-innocent backbone methine moiety, led to deprotonation/rearrangement and SiMe3/AlMe3 exchange to afford [(Me3AlCTp3-Ph)2Mg] and [(Me3AlCTp3-Me)Mg(AlMe4)], respectively, with monoanionic tripodal ligands. Treatment of sterically less demanding RCTp3-R′ with Mg(AlMe4)2 produced isostructural dicationic “metal-in-a-box” complexes of the type [(RCTp3-R′)2Mg][AlMe4]2 (R=Me, nBu; R′=H, Me). Utilization of the superbulky ligands MeCTp3-Ph and MeCTp3-tBu gave monocationic complexes [(MeCTp3-Ph)MgMe][AlMe4] and [(MeCTp3-tBu)MgMe][Al2Me7] as separated ion pairs. The reaction of Mg(AlMe4)2 with nBuCTp3-Ph led to the formation of the dimagnesium complex [{(nBuCTp3-Ph)Mg(AlMe4)}2(μ-CH3)], which features a bridging methyl moiety and terminal η1-coordinated tetramethylaluminato ligands. Isopropyl-substituted ligand MeCTp3-iPr emerged from further fine-tuning of the steric and electronic parameters and, upon reaction with Mg(AlMe4)2, gave (MeCTp3-iPr)Mg(AlMe4)2; this represents the first example of a magnesium bis(alkyl) complex with an intact RCTp3-R′ ligand. The exact ligand cone angles Θ° of all magnesium complexes were determined according to the mathematical analysis developed by Allen et al. [J. Comput. Chem. 2013, 34, 1189–1197].
Influence of the crystallization solvent on molecular and supramolecular structures of silver(I) tris(3-phenylpyrazolyl)methane complexes
Reger, Daniel L.,Semeniuc, Radu F.,Smith, Mark D.
, p. 3480 - 3494 (2007/10/03)
The compound [{HC(3-Phpz)3}Ag](BF4) (pz = pyrazolyl ring) has been prepared and shown to crystallize in four different forms depending on the solvent. Vapor-phase diffusion of diethyl ether into nitromethane solutions of the complex produces two polymorphs, an orthorhombic form (1) and triclinic form (2). Both polymorphs are coordination polymers constructed by a κ2-κ1 coordination of the tris(3-Phpz)methane units and have similar, but different, supramolecular structures. In 1 there are two independent chains linked by C-H...π interactions. In 2 only one type of chain is present, with a different internal structure than in 1. Non-covalent forces, mainly C-H...π interactions, organize the chains into sheets and the sheets into a final 3-D supramolecular structure in the case of 1, while in the case of 2 only a 2-D supramolecular structure forms. In contrast, vapor-phase diffusion of diethyl ether into acetonitrile or acetone solutions produces [{HC(3-Ph-pz)3}Ag{(CH 3)2CO}](BF4) (3) and [{HC(3-Phpz) 3}Ag{CH3CN}](BF4) (4). In these compounds, the ligand shows tripodal coordination to a single silver center and coordination of one solvent molecule to the metallic center. Both compounds form 3-D supramolecular structures organized by both C-H...π interactions and weak C-H...F hydrogen bonds and in the case of 4 π-π stacking. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Syntheses of Cationic, Six-Coordinate Cadmium(II) Complexes Containing Tris(pyrazolyl)methane Ligands. Influence of Charge on Cadmium-113 NMR Chemical Shifts
Reger, Daniel L.,Collins, James E.,Myers, Sheila M.,Rheingold, Arnold L.,Liable-Sands, Louise M.
, p. 4904 - 4909 (2008/10/09)
Treating a thf (thf = tetrahydrofuran) suspension of Cd(acac)2 (acac = acetylacetonate) with 2 equiv of HBF4·- Et2 results in the immediate formation of [Cd2(thf)5](BF4)4 (1). Crystallization of this complex from thf/CH2- Cl2 yields [Cd(thf)4](BF4)2 (2), a complex characterized in the solid state by X-ray crystallography. Crystal data: monoclinic, P21/n, a = 7.784(2) A, b = 10.408(2) A, c = 14.632(7) A, β = 94.64(3)°, V = 1181.5(6) A3, Z = 2, R = 0.0484. The geometry about the cadmium is octahedral with a square planar arrangement of the thf ligands and a fluorine from each (BF4)- occupying the remaining two octahedral sites. Reactions of [Cd2(thf)5](BF4)4 with either HC(3,5-Me2pz)3 or HC(3-Phpz)3 yield the dicationic, homoleptic compounds {[HC- (3,5-Me2pz)3]2Cd}(BF4)2 (3) and {[HC(3-Phpz)3]2Cd}(BF4)2 (4) (pz = 1-pyrazolyl). The solid state structure of 3 has been determined by X-ray crystallography. Crystal data: rhombohedral, R3, a = 12.236(8) A, c = 22.69(3) A, V = 2924(4) A3, Z = 3, R = 0.0548. The cadmium is bonded to the six nitrogen donor atoms in a trigonally distorted octahedral arrangement. Four monocationic, mixed ligand tris(pyrazolyl)methane-tris- (pyrazolyl)borate complexes {[HC(3,5-Me2pz)3][HB(3,5-Me2pz) 3]Cd}(BF4) (5), {[HC(3,5-Me2pz)3][HB(3-Phpz)3]- Cd}(BF4) (6), {[HC(3-Phpz)3][HB(3,5-Me2pz)3]Cd}(BF 4) (7), and {[HC(3-Phpz)3][HB(3-Phpz)3]Cd}(BF4) (8) are prepared by appropriate conproportionation reactions of 3 or 4 with equimolar amounts of the appropriate homoleptic neutral tris(pyrazolyl)borate complexes [HB(3,5-Me2pz)3]2Cd or [HB(3-Phpz)3]2Cd. Solution 113Cd NMR studies on complexes 3-8 demonstrate that the chemical shifts of the new cationic, tris(pyrazolyl)methane complexes are very similar to the neutral tris(pyrazolyl)borate complexes that contain similar substitution of the pyrazolyl rings.
