Alejandro J. Metta-Magaña

Design, Synthesis, and X‐Ray Crystal Structure of a Fullerene‐Linked Metal–Organic Framework

Given the unique structural and electronic properties of C60 , metal-organic frameworks (MOFs) containing C60 linkers are expected to exhibit interesting characteristics. A new hexakisfullerene derivative possessing two pairs of phenyl pyridine groups attached to two methano-carbon atoms located at the trans-1 positions was designed and synthesized. The four pyridyl nitrogen atoms define a perfectly planar rectangle. This new C60 derivative was used to assemble the first fullerene-linked two-dimensional MOF by coordination with Cd(2+) .

8-Amino-BODIPYs: structural variation, solvent-dependent emission, and VT NMR spectroscopic properties of 8-R2N-BODIPY.

New 8-NR2-BODIPYs, R2 = H(i)Pr (3a), H(i)Bu (3b), and Et2 (4), are reported. Restricted rotation about the C8-N bond in such molecules has been observed for the first time (3a and 3b) and evaluated using VT NMR. The fluorophores 3a and 3b are blue emitters, and the efficiency of the emission is closely related to the polarity of the solvent, e.g., hexane > toluene > DCM > THF > MeOH > H2O, an effect also noted by emission variation in alcohol solvents H(CH2)nOH, n = 1-6. In mixed-solvent systems, addition of 10-15% of the more polar solvent results in transformation of the emission properties to those of the bulk polar solvent. Compound 4 has zero emission in all solvents. The crystal structures of 3a, 3b, and 4 are reported, along with that of the parent 8-NH2-BODIPY (2). Compounds 2, 3a, and 3b exhibit trigonal planar N atoms which are coplanar with the BODIPY core; 4 exhibits a very significant distortion that breaks the planarity of the extended BODIPY π system due to the steric impact of the two ethyl groups, an observation that explains the lack of emission for 4.

High yield synthesis of a new fullerene linker and its use in the formation of a linear coordination polymer by silver complexation

A new hexakis-fullerene adduct with two 4,5-diazafluorene groups strategically located at trans-1 positions to allow linear polymerization was selectively synthesized in very high yield. By reaction with Ag(triflate), a one dimensional metal-organic coordination polymer was obtained.

Dehydrogenative Dimerization of Di‐tert‐butyltin Dihydride Photochemically and Thermally Catalyzed by Iron and Molybdenum Complexes

Dehydrogenative coupling of tertiary stannanes, R3SnH, catalyzed by a transition metal is known to produce distannanes, R3Sn SnR3, whereas a mixture of cyclic and linear oligoor polystannanes is obtained from the analogous dehydrogenative coupling of secondary stannanes, R2SnH2. [2–4] 1,2-Dihydrodistannanes are of significant interest as bifunctional model compounds to mimic the properties of polystannanes and they are excellent precursors for further derivatization. However, until a report by Uhlig et al. there were no well-defined methodologies for the synthesis of 1,2dihydrodistannanes. The Uhlig synthesis involves a two-step reaction sequence that starts with the reaction of tertbutylmagnesium chloride with tin tetrachloride in an overall yield of 2.5%. We now report the photochemical and thermal dehydrogenative dimerization of tBu2SnH2 (1) to tBu2HSn SnHtBu2 (2), catalyzed by the iron catalysts 3 and 4 and their molybdenum analogues 5 and 6.

A Tripodal Ligand Constructed from Mesoionic Carbene Donors

A tripodal ligand constructed solely from mesoionic carbene donors is reported. The donor strength of this ligand is lower than most imidazol-2-ylidene-based tris(carbene)borate ligands, as measured by IR spectroscopy of {NiNO}(10) and {Mn(CO)3}(+) derivatives. The attenuated donor strength is proposed to be due to the collective electron-withdrawing effect of the ligands aryl substituents.

Unexpected Isomerism in cis‐2 Bis(pyrrolidino)[60]Fullerene Diastereomers

Similar yet different: A one-step regio- and diastereoselective synthesis of three new bis(pyrrolidine)[60]fullerenes, one cis-1 and two unprecedented cis-2 diastereoisomers, is reported. The compounds are easily purified using simple chromatographic techniques, and were fully characterized by spectroscopic techniques and X-ray crystallography. A mechanism for the isomeric conversion observed is proposed.

Solvothermal synthesis and crystal structure of a 3-D hexagonal metal-porphyrin coordination network

A hexagonal-shaped hybrid metal-porphyrin framework containing 5,15-di(4-pyridyl)-10,20-diphenylporphyrin (trans-H2DPyP) and Zn(NO3)26H2O in DMF has been self-assembled solvothermally. The solvothermal reaction of Zn(II) with conformationally versatile 5,15-di(4-pyridyl)-10,20-diphenylporphyrin, which can coordinate axially to two ligands, resulted in metalation of the porphyrin core and then self-coordination of the metalated porphyrin-produced single crystals of 3-D polymeric arrays. The trans-ZnDPyP framework is thermally stable at 450 °C and allows solvent exchange without losing the crystal structure.

Phosphine induced migratory CO insertion into the Fe–CH2 bond of the organometallic polymer -[(η5-C5H4)Fe(CO)2CH2SiMe2]n- and characterization of model iron complexes

Thermal and photochemical treatment of 1-sila-3-ferracyclobutane, (eta(5)C(5)H(4))Fe(CO)(2)CH(2)SiMe(2) (1) results in ring-opening polymerization (ROP). Phosphine-induced migratory CO insertion into the Fe-CH(2) bond of the preformed polymer, -[(eta(5)-C(5)H(4))Fe(CO)(2)CH(2)SiMe(2)](n)- (2) results in either linear polymers, -[(eta(5)-C(5)H(4))Fe(CO)(PR(3))C(O)CH(2)SiMe(2)](n)- [R(3) = Me(2)Ph (3), Ph(3) (4)] or diphosphine bridged polymers, -{[(eta(5)-C(5)H(4))Fe(CO)C(O)CH(2)SiMe(2)](2)(P-P)}(n)- [P-P = dppe (5), dppp (6), dppb (7), trans-dppen (8), dmpe (9); dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,2-bis(diphenylphosphino)propane, dppb = 1,2-bis(diphenylphosphino)butane, cis-dppen = cis-1,2-bis(diphenylphosphino)ethylene, dmpe = 1,2-bis(dimethylphosphino)ethane]. The analogous model complexes, {[(eta(5)-C(5)H(5))Fe(CO)C(O)CH(3)](2)P-P} [P-P = dppp (10), dppb (11), trans-dppen (12), dmpe (13)] were synthesized and characterized as models of the acylated polymers. The X-ray crystal structure of 11 and 13 were determined to establish the bridging nature of the diphosphines in the model complexes and to get insight of the crystal packing.

Methyl transfer from Fe (and Mo) to Sn: formation of (eta(5)-C(5)H(5))M(CO)(n)Sn(t)Bu(2)Me (M = Fe, n = 2; M = Mo, n = 3) complexes from photochemical irradiation of (eta(5)-C(5)H(5))M(CO)(n)Me and (t)Bu(2)SnH(2).

Formation of an Sn-CH(3) bond, concomitantly with an Sn-M (M = Fe, Mo), is readily achieved from the photochemical reactions of (t)Bu(2)SnH(2) with (eta(5)-C(5)H(5))M(CO)(n)Me (M = Fe, n = 2; M = Mo, n = 3) via the intermediacy of (eta(5)-C(5)H(5))M(CO)(n)Sn(t)Bu(2)H.

Synthesis and characterization of a trans-1 hexakis-fullerene linker that forms crystalline polymers with silver salts

A new flexible hexakis-fullerene adduct with two bis(pyridin-4-ylmethyl)malonate groups located at trans-1 positions was synthesized. Via reaction with Ag(PF6) under two different conditions, two new 1D coordination polymers were obtained; under a nitrogen atmosphere, the silver ions are connected by argentophilic interactions but under an ambient atmosphere, the silver ions exhibit no interaction between them but coordination to the (H2PO4)(-) ions.