Nitrile ligands for controlled synthesis of alkynyl-ruthenium based homo and hetero bimetallic systems

Dicyanobenzene passivated perovskite solar cells with enhanced efficiency and stability

Dicyanobenzene (DCB), a weak Lewis base, effectively passivates perovskite films by eliminating residual PbI2, enhancing crystallinity, and reducing trap state density, thus enhancing perovskite solar cell performance and stability.

Cyanoferrocenes as redox-active metalloligands for coordination-driven self-assembly

Ferrocene-based Lewis bases have found utility as metalloligands in a wide variety of applications. The coordination chemistry of cyanoferrocenes however, is underexplored. Herein, we describe a new synthetic protocol for the generation of cyanoferrocenes. The coordination chemistry of these metalloligands to [Cu(NCMe)4][PF6], [(PPh3)2Cu(NCMe)2][PF6] and [(dppf)Cu(NCMe)2][PF6] salts has been explored, providing crystallographic evidence of cluster and polymeric forms of 1,1'- and 1,2-dicyanoferrocene complexes. The stability of the complexes and ligand dissociation were found to be strongly solvent-dependent.

Cationic tri(ferrocenecarbonitrile)silver(I)

The synthesis of the tri-coordinated ferrocenecarbonitrile silver(I) complex [Ag(N≡CFc)3]OTf (3) is reported. Its electrochemical behavior shows that the three ferrocenyl units are oxidized in a very close potential range. In addition, the molecular structure of 3 in the solid state is discussed, showing that silver(I) is exclusively coordinated by three ferrocenecarbonitrile molecules.

1,2-Dicyanoferrocene: synthesis and characterization

A convenient synthesis of 1,2-dicyanoferrocene (3) was developed by using 2,4-dinitrofluorobenzene as a dehydrating agent for the treatment of 1,2-ferrocenedicarbaldehyde dioxime (2) to give 3 in yields exceeding 80%. Compounds 2 and 3 have been characterized by IR and NMR (1H, 13C{1H}) spectroscopy and by electrochemistry (cyclic voltammetry and square-wave voltammetry). Furthermore, the molecular structures of 2 and 3 in the solid state have been determined by single-crystal X-ray crystallographic studies.

How do nitriles compare with isoelectronic alkynyl groups in the electronic communication between iron centers bridged by phenylenebis- and -tris(nitrile) ligands? An electronic and crystal-structure study

Density functional theory (DFT) calculations on the model [{FeCp(dpe)}(2){1,4-C(6)H(4)(CN)(2)}](2+) (3(2+); dpe = diphosphinoethane) of salts of the cations [{FeCp(dppe)}(2){1,4-C(6)H(4)(CN)(2)}](2+) (1(2+); dppe = 1,2-bis[diphenyldiphosphino]ethane) and [{FeCp*(CO)(2)}(2){1,4-C(6)H(4)(CN)(2)}](2+) (2(2+)), for which the X-ray crystal structures have been determined, as well as on its isomer [{FeCp(dpe)}(2){1,3-C(6)H(4)(CN)(2)}](2+) (4(2+)) and on the related complex [{FeCp(dpe)}(3){1,3,5-C(6)H(3)(CN)(3)}](3+) (5(2+)), indicate that the highest occupied molecular orbitals (HOMOs) of these compounds are localized on the metal centers with negligible participation of the C(6) ring. Thus, the poly(nitrile)phenylene ligand efficiently quenches the electronic communication between the metal centers. This is at variance with the related isoelectronic polyacetylene phenylene complexes, in which the iron centers have been shown to be electronically coupled. Consistently, apart from the case of 3(3+), which shows some degree of delocalization, all of the oxidized forms of 3(2+), 4(2+), and 5(2+) can be described as class II, localized mixed-valent species, in agreement with the electrochemical data showing two close oxidation potentials around 1 V vs FeCp*(2). This is at variance with the p-phenylene-bridged biethynyldiiron analogue, for which extended electronic delocalization was earlier shown to provide greater degree of delocalization of the mixed valency. Time-dependent DFT calculations on 3(2+), 4(2+), and 5(2+) indicate that the lowest-energy absorption band is associated with metal-to-ligand charge-transfer transitions involving the metallic HOMOs and the two lowest unoccupied molecular orbitals that derive from the lowest π*(phenylene) orbitals with some π*(CN) bonding admixture.

Visible-light photolytic synthesis of multinuclear and dendritic iron-nitrile cationic complexes

Multinuclear and dendritic iron-nitrile piano-stool cationic complexes were synthesized in quantitative yield by a single-step synthesis involving visible-light photolysis of the complex [CpFe(eta(6)-toluene)][PF6]. This synthetic strategy was applied to mono-, bis- and tris-nitrile ligands and to new nitrile-terminated dendrimers containing 9, 27, and 81 tethers. All the synthesized products are deep red solids or red waxy products, highly stable to air and moisture. They were characterized by (1)H, (13)C, and (31)P NMR, elemental analysis, UV-vis spectroscopy, and cyclic voltammetry (single reversible oxidation wave to Fe(III)). Only the para-disubstituted arene dinitrile diiron complex shows two separated reversible waves indicating some electronic communication between the iron centers through the nitrile ligands.