Leopoldo Delia Ciana

Bio: Leopoldo Delia Ciana is an academic researcher from State University of New York System. The author has contributed to research in topics: Melting point & Mass spectrometry. The author has an hindex of 2, co-authored 2 publications receiving 157 citations.

Construction of Preorganized Polytopic Ligands via Palladium-Promoted Cross-Coupling Reactions

Abstract: Rigid preorganized multitopic ligands have been designed and synthesized. The Pd(0)-catalyzed cross-coupling reactions between ethynylated derivatives of bipyridine or terpyridine and the corresponding bipyridine or terpyridine halides or triflates provide access to various homo-ditopic, hetero-ditopic, homo-tritopic, and hetero-tritopic ligands bearing acetylene or diphenylacetylene central units in fair to excellent yields. Optimal conditions were found with [Pd(PPh3)2Cl2], CuI in THF and diisopropylamine at rt, or with [Pd(PPh3)4] in benzene and diisopropylamine at 80 °C. When a phenylethynyl group is present in the molecule, the relevant conditions involve [Pd(PPh3)4] in n-propylamine at 60 °C. Oxidative dimerization of the ethynylated derivatives in the presence of cupric salts and oxygen gives the corresponding homo-ditopic ligands bearing diacetylene or diphenyldiacetylene as a spacer in good yields. These methods provide a practical approach to the rational design of multichelating ligands for coo...

Self-Assembly Triangular and Square Rhenium(I) Tricarbonyl Complexes: A Comprehensive Study of Their Preparation, Electrochemistry, Photophysics, Photochemistry, and Host−Guest Properties

Abstract: A series of self-assembly macrocyclic compounds featuring fac-Re(CO)3X (X = Cl or Br) as corners and linear bipyridyl bridging ligands have been prepared and characterized. Depending on the lengths as well as the bonding angles of the bridging ligands, the resulting geometries of these macrocyclic complexes are squares {[ClRe(CO)3(μ-DPB)]4 (3) and [ClRe(CO)3(μ-AZP)]4 (4)}, triangles {[BrRe(CO)3(μ-BPDB)]3 (6) and [BrRe(CO)3(μ-BPDDB)]3 (7)}, or a dimeric species {[ClRe(CO)3(μ-BPET)]2 (5)}. A general mechanism for the self-assembly processes involving soluble intermediates is proposed. The photophysical properties of these macrocyclic compounds are dominated by the characteristics of the lowest excited states which vary from metal-to-ligand charge transfer (MLCT) to ligand-localized π → π* or n → π* transitions for the different molecules. Square 3 and triangles 6 and 7 are luminescent in room-temperature solution while square 4 and dimer 5 are nonemissive. An energy transfer mechanism from the MLCT excited ...

Template-Directed Synthesis, Excited-State Photodynamics, and Electronic Communication in a Hexameric Wheel of Porphyrins

Abstract: To investigate new architectures for molecular photonics applications, a shape-persistent cyclic hexameric architecture (cyclo-Zn3Fb3U-p/m) has been prepared that is comprised of three free base (F...

Organic triplet emissions of arylacetylide moieties harnessed through coordination to [Au(PCy(3))]+. Effect of molecular structure upon photoluminescent properties.

Abstract: A family of mono- and binuclear Cy3P-supported gold(I) complexes containing various π-conjugated linear arylacetylide ligands, including the two homologous series (Cy3P)Au(C⋮CC6H4)n-1(C⋮CPh) and (Cy3P)Au(C⋮CC6H4)nC⋮CAu(PCy3) (n = 1−4), have been prepared. X-ray crystal analyses revealed no intermolecular aurophilic interactions in their crystal lattice. The lowest-energy singlet transitions are predominately intraligand in nature and exhibit both phenyl and acetylenic 1(ππ*) character. Strong photoluminescence is detected in solid and solution states under ambient conditions, with lifetimes in the microsecond regime. For complexes with a single arylacetylide group, only phosphorescence from the arylacetylide 3(ππ*) state is observed. Vibrational spacings in the solid-state emission spectra can be attributed to a combination of phenyl ring deformation and symmetric phenyl ring and C⋮C stretches. Additional delayed-fluorescence emission is recorded for complexes with multiple p-arylacetylide units, and this...