Supramolecular Porphyrin-Based Metal-Organic Frameworks with Fullerenes: Crystal Structures and Preferential Intercalation of C70.

The syntheses and characterization of two new porphyrin-based metal-organic frameworks (P-MOFs), through the complexation of 5,10,15,20-tetra-4-pyridyl-21 H,23 H-porphine (H2 TPyP) and copper(II) acetate (CuAcO) in the presence of the fullerenes C60 or C70 are reported. Complex 1 was synthesized in conjunction with C60 , and this reaction produced a two-dimensional (2D) porous structure with the composition CuAcO-CuTPyP⊃m-dichlorobenzene (m-DCB), in which C60 molecules were not intercalated. Complex 2 was synthesized in the presence of C70 , generating a three-dimensional (3D) porous structure, in which C70 was intercalated, with the composition CuAcO-CuTPyP⋅C70 ⊃m-DCB⋅CHCl3 . The structures of these materials were determined by X-ray diffraction to identify the supramolecular interactions that lead to 2D and 3D crystal packing motifs. When a combination of C60 and C70 was employed, C70 was found to be preferentially intercalated between the porphyrins.

Exploring the limits of frustrated Lewis pair chemistry with alkynes: detection of a system that favors 1,1-carboboration over cooperative 1,2-P/B-addition.

The zirconocene complex [{(C6F5)2B-(CH2)3-Cp}(Cp-PtBu2)ZrCl2] (6; Cp=cyclo-C5H4) was prepared by hydroboration of [(allyl-Cp)(Cp-PtBu2)ZrCl2] (5) with HB(C6F5)2 ("Piers' borane"). It represents a frustrated Lewis pair (FLP) in which both the Lewis acid and the Lewis base were attached at the metallocene framework. Its reaction with 1-pentyne did not result in the 1,2-addition of or deprotonation reaction by the FLP, but rather in the 1,1-carboboration of the triple bond, thereby obtaining a Z/E mixture (1.2:1) of the respective organometallic substituted alkenes 7. The analogous reaction of 1-pentyne with the phosphorous-free system [{(C6F5)2B-(CH2)3-Cp)}CpZrCl2] (9) gave the respective 1,1-carboboration products ((Z)-10/(E)-10≈1.3:1).

Evidence for a rapid degenerate hetero-Cope-type rearrangement in [Cp*W(S)2S-CH2-CH=CH2].

Treatment of the salt [PPh(4)]+[Cp*W(S)3]- (6) with allyl bromide gave the neutral complex [Cp*W(S)2S-CH2-CH=CH2] (7). The product 7 was characterized by an X-ray crystal structure analysis. Complex 7 features dynamic NMR spectra that indicate a rapid allyl automerization process. From the analysis of the temperature-dependent NMR spectra a Gibbs activation energy of DeltaG(not equal) (278 K) approximately 13.7+/-0.1 kcal mol(-1) was obtained [DeltaH(not equal) approximately 10.4+/-0.1 kcal mol(-1); DeltaS(not equal) approximately -11.4 cal mol(-1) K(-1)]. The DFT calculation identified an energetically unfavorable four-membered transition state of the "forbidden" reaction and a favorable six-membered transition state of the "Cope-type" allyl rearrangement process at this transition-metal complex core.

Mono{hydrotris(mercaptoimidazolyl)borato} complexes of manganese(II), iron(II), cobalt(II), and nickel(II) halides.

A series of [Tm(Me)M(mu-Cl)]2 and Tm(R)MCl (Tm(R) = tris(mercaptoimidazolyl)borate; R = Me, tBu, Ph, 2,6-iPr2C6H3 (Ar); M = Mn, Fe, Co, Ni) complexes have been prepared by treatment of NaTm(Me) or LiTm(R) with an excess amount of metal(II) chlorides, MCl2. Treatment of Tm(R)MCl (R = tBu, Ph, Ar) with NaI led to a halide exchange to afford Tm(R)MI. The molecular structures of [Tm(Me)M(mu-Cl)]2 (M = Mn, Ni), [Tm(Me)Ni(mu-Br)]2, Tm(tBu)MCl (M = Fe, Co), Tm(Ph)MCl (M = Mn, Fe, Co, Ni), Tm(Ar)MCl (M = Mn, Fe, Co, Ni), Tm(Ph)MI (M = Mn, Co), and Tm(Ar)MI (M = Fe, Co, Ni) have been determined by X-ray crystallography. The Tm(R) ligands occupy the tripodal coordination site of the metal ions, giving a square pyramidal or trigonal bipyramidal coordination geometry for Tm(Me)M(mu-Cl)]2 and a tetrahedral geometry for the Tm(R)MCl complexes, where the S-M-S bite angles are larger than the reported N-M-N angles of the corresponding hydrotris(pyrazolyl)borate (Tp(R)) complexes. Treatment of Tm(Ph)2Fe with excess FeCl2 affords Tm(Ph)FeCl, indicating that Tm(R)2M as well as Tm(R)MCl is formed at the initial stage of the reaction between MCl2 and the Tm(R) anion.