ABSTRACT
The title compound, C6H13N2 +·Cl-, is as an amidinium salt that was isolated as unexpected product from the reaction between aceto-nitrile, chloro-form and pyrrolidine under refluxing conditions. The packing features two N-Hâ¯Cl hydrogen bonds to generate centrosymmetric tetra-mers (two cations and two anions) and van der Waals inter-actions.
ABSTRACT
Yellow crystals of the title compound 3-amino-4-nitro-benzyl acetate, C9H10N2O4, were isolated from the reaction of acetic anhydride with (5-amino-2-nitro-phen-yl)methanol, prepared from reduction of commerically available 5-amino-2-nitro-benzoic acid with borane-THF. The mol-ecule is essentially planar (r.m.s. deviation = 0.028â Å). The mol-ecules are linked by inter-molecular N-Hâ¯O hydrogen-bonding inter-actions between the carbonyl and amine groups, forming a zigzag chain along the b-axis direction lying in a plane parallel to (-102). The chains are stacked along the c axis by π-π inter-actions [centroid-centroid distances = 3.6240â (3) and 3.5855â (4)â Å]. A strong intra-molecular N-Hâ¯O hydrogen-bonding inter-action is observed between the nitro group and the amine group [2.660â (2)â Å].
ABSTRACT
The cationic pseudo-square-planar complex tetrakis(1-methyl-2,3-dihydro-1H-imidazole-2-thione-κS)gold(III) trichloride sesquihydrate, [Au(C4H6N2S)4]Cl3·1.5H2O, was isolated as dark-red crystals from the reaction of chloroauric acid trihydrate (HAuCl4·3H2O) with four equivalents of methimazole in methanol. The Au(III) atoms reside at the corners of the unit cell on an inversion center and are bound by the S atoms of four methimazole ligands in a planar arrangement, with S-Au-S bond angles of approximately 90°.
ABSTRACT
Previously, hydridotris(pyrazolyl)borate (Tp) Ru(II) alkyl and aryl complexes of the type TpRu(L)(NCMe)R (R = methyl or aryl; L = charge-neutral two-electron donating ligand) were demonstrated to activate aromatic C-H bonds. To determine the impact of replacing the anionic Tp ligand with charge-neutral poly(pyrazolyl)alkane ligands, [(C(pz)4)Ru(P(OCH2)3CEt)(NCMe)Me][BAr'4] (pz = pyrazolyl, BAr'4 = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) was prepared. Heating a C6D6 solution of [(C(pz)4)Ru(P(OCH2)3CEt)(NCMe)Me][BAr'4] with 1 equiv of NCMe resulted in C-H activation of the 5-position of a pyrazolyl ring to yield [(κ(3)-(N,C(5),N)C(pz)4)Ru(P(OCH2)3CEt)(NCMe)2][BAr'4] and CH4. Intramolecular C-H activation of the 5-position of a pyrazolyl ring also occurred when (η(6)-p-cymene)Ru(P(OCH2)3CEt)(Br)Ph was heated in the presence of C(pz)4 to yield [(κ(3)-N,C(5),N)C(pz)4]Ru(P(OCH2)3CEt)(NCMe)Br and C6H6. Density functional theory calculations revealed that the different reactivities of TpRu(P(OCH2)3CEt)(NCMe)R and [(C(pz)4)Ru(P(OCH2)3CEt)(NCMe)Me][BAr'4] result from the stronger binding of the Tp pyrazolyl rings to Ru(II) compared to that of C(pz)4.
ABSTRACT
Treatment of RuCl(2)(PPh(3))(3) with sodium 2,2,2-tris(pyrazolyl)ethoxide [NaOCH(2)C(pz)(3); pz = pyrazolyl] affords the asymmetric heteroscorpionate complex cis-(Ep(OX))RuCl(PPh(3))(2) (1), (Ep(OX) = κ(3)-N,N,O-OCH(2)C(pz)(3)), which can be converted to Ru(II) compounds (2-6), (Ep(OX))RuCl(L)(L') [(2) L = PPh(3), L' = P(OCH(2))(3)CEt; (3) L = L' = P(OCH(2))(3)CEt; (5) L, L' = PPh(3), CO; (6) L = L' = CO]. Compounds 1 and 3 react with CHCl(3) at 60 and 100 °C, respectively, to yield cationic tris(pyrazolyl)methane Ru(II) complexes, [(κ(3)-N,N,N-Mp)RuCl(L)(2)]Cl [Mp = HC(pz)(3); (7) L = PPh(3); (8) L = P(OCH(2))(3)CEt]. The complexes have been characterized by (1)H, (13)C, and (31)P{(1)H} NMR spectroscopy, elemental analysis, high resolution mass spectrometry, and cyclic voltammetry. Complexes 1 and 3 have also been characterized by single crystal X-ray analysis.
ABSTRACT
The reaction of N-heterocyclic carbene, L:, with BeCl(2) quantitatively yields L:BeCl(2)1 (L: = :C{N(2,6-Pr(i)(2)C(6)H(3))CH}(2)). The carbene-stabilized beryllium borohydride monomer L:Be(BH(4))(2)2 is prepared by the reaction of 1 with LiBH(4). Compound 3, prepared by the reaction of 2 with Na(2)[Fe(CO)(4)]·dioxane, represents an unusual "dual reduction" of the imidazole ring (i.e., hydroboration of the CâC backbone and hydrogenation of the C2 carbene center).
ABSTRACT
Potassium graphite reduction of L:Ga(Mes)Cl(2) [L: = :C{(i-Pr)NC(Me)}(2), Mes = 2,4,6-Me(3)C(6)H(2)] (1) in hexane yields the organogallium dimer L:(Mes)(Cl)Ga-Ga(Cl)(Mes):L (2), while potassium reduction of 1 in toluene affords the neutral aromatic Ga(6) octahedron L:Ga[Ga(4)Mes(4)]Ga:L (3).
ABSTRACT
Reaction of RLi with lead(II) bromide affords the diaryl lead(II) compounds PbR2 (R1 = 2,4,6-triphenylphenyl, 1; R2 = 2,6-bis(1'-naphthyl)phenyl, 2), which have monomeric, carbene-like structures with bent two-coordinate Pb(II) centers.
ABSTRACT
Potassium reduction of RZn(mu-I)2Li(OEt2)2 (R = [{(2,6-Pri2C6H3)N(Me)C}2CH]) affords the second compound with a Zn-Zn bond, RZn-ZnR. The air- and moisture-sensitive title compound was characterized by 1H NMR, elemental analyses, and single-crystal X-ray diffraction. The Zn-Zn bond was determined to be 2.3586(7) A; this value is only about 0.05 A longer than the Zn-Zn bond reported for Cp*Zn-ZnCp* (Cp* = C5Me5), the first reported compound with a Zn-Zn bond. In addition, density functional theory (DFT) computations on related model RZn-ZnR compounds provide insight into the intriguing Zn-Zn bond.
ABSTRACT
The zirconocene-complexed dibismuthene, Cp2Zr(BiR)2 (Cp = C5H5; R = C6H3-2,6-Mes2), was prepared by the reaction of sodium metal with Cp2ZrCl2 and RBiCl2. The air- and moisture-sensitive dark reddish/brown compound is the first organometallic compound containing Bi-Zr bonds and the only example of a ZrBi2 ring. Moreover, our computations on associated model systems offer insight into the nature of the interaction of the heaviest dipnictene with a metallocene center.
ABSTRACT
Reaction of lead(II) chloride with biphenylmagnesium bromide yields Bp(3)Pb-PbBp(3) and [(THF)(3)Mg(mu-Cl)(3)Mg(THF)(3)][Pb(PbBp(3))(3)](Bp = biphenyl), which, upon single crystal X-ray crystallographic analysis, reveals an interesting variation of Pb-Pb bond distances.
