I. Photophysics and Photochemistry of Molybdenum-Oxo Complexes. II. Synthesis of a Ferrocene-Based Monomer for Use in Ring-Opening Metathesis Polymerization.

The brick-red ferrocenophene 1,4-(3,3\sp\prime-bis(1,1-dimethylpentyl)-1,1\sp\prime-ferrocenediyl) -1,3-butadiene was prepared via a six-step synthetic route. It was isolated and characterized for use as a monomer in Ring Opening Metathesis Polymerization. Fluorescent molybdenum(V)-oxo complexes such as \rm MoOCl\sb4(H\sb2O)\sp- undergo thermal and photochemical reactions with the series of phosphines \rm PEt\sb2,\ PEt\sb3Ph,\ PEtPh\sb2 and PPh\sb3 as oxygen atom acceptors. PEt\sb3 reacts spontaneously to form several products: \rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack,\ (PPh\sb4)\sb2\lbrack MoOCl\sb5\rbrack{\cdot}2CH\sb2Cl\sb2, and a maroon oil that contains \rm OPEt\sb3,\ MoOCl\sb2(PEt\sb3)\sb3 and \rm MoCl\sb4(PEt\sb3)\sb2. Both \rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack and OPEt\sb3 are products of an oxygen atom transfer reaction. PEt\sb2Ph and PEtPh\sb2 also produce the corresponding phosphine oxides, but only under irradiation. The molybdenum(III) complex \rm MoCl\sb3(OPEt\sb2Ph)\sb2(PEt\sb2Ph) was isolated from irradiated Mo(V)-PEt2Ph solutions. PPh\sb3 is not oxidized under these conditions. Selective irradiation of the longer-wavelength molybdenum(V) absorption bands leads to similar photoredox reactions, but much more slowly. The electronic absorption spectra of the irradiated Mo(V)-PEtPh\sb2 and Mo(V)-PPh\sb3 solutions are similar to those of the known oxomolybdenum(V) complex MoOCl\sb3(dppe), whose X-ray crystal structure is also reported. The spectroscopic and photochemical properties of these species were also compared with those of the known oxomolybdenum(IV) complexes MoOCl(dppe)\sb2\sp+ (dppe = 1,2-bis(diphenylphosphino)ethane) and MoOCl(CN-t-Bu)\sb4\sp+ and the new dimethoxymolybdenum(IV) complex \rm Mo(OCH\sb3)\sb2(CN-t-Bu)\sb4\sp{2+}. All three of these compounds are luminescent in the solid state at room temperature and at 77 K, with MoOCl(CN-t-Bu)\sb4\sp{+} also exhibiting luminescence in \rm CH\sb2Cl\sb2 solution at room temperature. Luminescence lifetimes are $\u3e$1 $\mu$s for all three complexes; the transition is assigned as phosphorescence, \rm\sp3E\lbrack(d\sb{xy})\sp1(d\sb{xz,yz})\sp1\rbrack\to\sp{1A}\sb1\lbrack(d\sb{xy})\sp2\rbrack(C\sb{4v}).

2-(9-Anthrylmethyl­ideneamino)-4-methyl­phenol

The title compound, C22H17NO, is a novel Schiff base synthesized via a condensation reaction between 9-anthracenecarboxaldehyde and 2-amino-p-cresol. The asymmetric unit contains two independent mol­ecules that are joined by an O—H⋯OH hydrogen bond. An intra­molecular O—H⋯N hydrogen bond occurs in each mol­ecule. π-stacking about inversion centers was observed between adjacent phenol rings [centroid–centroid distance = 3.850 (2) Å] and adjacent anthracene rings [centroid–centroid distance = 3.834 (2) Å]. The C—N=C—C torsion angles between the phenol and anthracene rings are close to 180° with values of 174.06 (15) and 179.85 (14)°

2-(9-Anthrylmethyl­­idene­amino)-4-methyl­phenol

The title compound, C22H17NO, is a novel Schiff base synthesized via a condensation reaction between 9-anthracenecarboxaldehyde and 2-amino-p-cresol. The asymmetric unit contains two independent mol­ecules that are joined by an O—H⋯OH hydrogen bond. An intra­molecular O—H⋯N hydrogen bond occurs in each mol­ecule. π-stacking about inversion centers was observed between adjacent phenol rings [centroid–centroid distance = 3.850 (2) Å] and adjacent anthracene rings [centroid–centroid distance = 3.834 (2) Å]. The C—N=C—C torsion angles between the phenol and anthracene rings are close to 180° with values of 174.06 (15) and 179.85 (14)°

The Synthesis, Photophysical Characterization, and X‐Ray Structure Analysis of Two Polymorphs of 4,4′‐Diacetylstilbene

A palladium(II) acetate‐catalyzed synthesis of 1 that utilizes the novel triazene 1‐{4‐[(E)‐morpholin‐4‐yldiazenyl]phenyl}ethanone as a synthon is described. The room temperature absorption spectra of 1 in various solvents exhibited a π→π* transition in the range of 330–350 nm. Compound 1 was observed to be luminescent, with room‐temperature solution and solid‐state emission spectra that exhibited maxima in the range 400–500 nm. All room‐temperature absorption and emission spectra exhibited some degree of vibrational structure. The emission spectrum of 1 at 77 K in propanenitrile glass was broad and featureless with a maximum at 447 nm. Compound 1 crystallized as a yellow and colorless polymorph. X‐Ray structure analyses of both of these polymorphs and 1‐{4‐[(E)‐morpholin‐4‐yldiazenyl]phenyl}ethanone are presented

Crystal structure of [N,N′-bis(4-methylphenyl)-1,2-diphenylethane-1,2-diimine-κ2N,N′]dichloridopalladium(II) methanol monosolvate

The title compound, [PdCl2(C28H24N2)]·CH3OH, was prepared from the reaction of PdCl2(DMSO)2 (DMSO is dimethyl sulfoxide) and N,N′-bis(4-methylphenyl)-1,2-diphenylethane-1,2-diimine in methanol. The chelating diimine core of the title compound deviates slightly from planarity, with an N—C—C—N torsion angle of 5.3 (3)°. Delocalization in the diimine core is indicated by N—C and C—C bonds that are, respectively, longer and shorter than those found in related nonchelating diimines. The distorted square-planar coordination environment around the PdII atom is manifested as bond angles that are smaller and larger than 90°, and palladacycle torsion angles of −173.22 (16) and 167.06 (16)°. These deviations are attributed to the small bite angle of 79.13 (8)° of the diimine chelate. The crystal packing exhibits weak intermolecular hydrogen-bonding interactions involving aromatic H atoms, Cl atoms and intercalated methanol solvent molecules, defining layers parallel to (010)

Crystal structure of [N,N′-bis­­(4-methyl­phen­yl)-1,2-di­phenyl­ethane-1,2-di­imine-κ2N,N′]di­chlorido­palladium(II) methanol monosolvate

The title compound, [PdCl2(C28H24N2)]·CH3OH, was pre­pared from the reaction of PdCl2(DMSO)2 (DMSO is di­methyl sulfoxide) and N,N′-bis­(4-methyl­phen­yl)-1,2-di­phenyl­ethane-1,2-di­imine in methanol. The chelating di­imine core of the title compound deviates slightly from planarity, with an N—C—C—N torsion angle of 5.3 (3)°. Delocalization in the di­imine core is indicated by N—C and C—C bonds that are, respectively, longer and shorter than those found in related nonchelating di­imines. The distorted square-planar coordination environment around the PdII atom is manifested as bond angles that are smaller and larger than 90°, and palladacycle torsion angles of −173.22 (16) and 167.06 (16)°. These deviations are attributed to the small bite angle of 79.13 (8)° of the di­imine chelate. The crystal packing exhibits weak inter­molecular hydrogen-bonding inter­actions involving aromatic H atoms, Cl atoms and inter­calated methanol solvent mol­ecules, defining layers parallel to (010)

N-[4-(Morpholinodiazen­yl)phen­yl]acetamide

The title compound, C12H16N4O2, is a member of a family of morpholine-substituted aromatic diazenes. Conjugation of the diazene group π-system and the lone pair of electrons of the morpholine N atom is evidenced by a lengthened N=N double bond of 1.2707 (19) Å and a shortened N—N single bond of 1.346 (2) Å. The bond angles at the morpholine N atom range from 113.52 (14) to 121.12 (14)°, indicating some degree of sp2 hybridization. The morpholine ring adopts a conventional chair conformation with the diazenyl group in the equatorial position. The diazenyl and acetamido groups are both twisted relative to the plane of the benzene ring by 12.3 (2) and 25.5 (3)°, respectively

Electronic spectrum and crystal structure of fac-MoOCl\u3csub\u3e3\u3c/sub\u3e(dppe)

X-ray analysis of the oxomolybdenum(V) complex MoOCl3(dppe) (dppe = 1,2-bis(diphenylphosphino)ethane) shows that it is the facial isomer. (C26H24Cl1MoOP2, space group P21/n, a = 13.217(1), b = 12.8935(8), c = 16.0578(9) Å, β= 99.967(5)°, V = 2695.1(6) Å3, Z = 4, R = 0.038 for 6228 data with l \u3e 1σ(I).) The electronic absorption spectrum of the title compound is also compared with those of other oxomolybdenum(V) complexes. © 1998 Elsevier Science Ltd. All rights reserved