Syntheses,characterizations, and crystal structures of tri‐ and diorganotin (IV) derivatives with 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole

A series of organotin(IV) complexes with 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole (HL) of the type R₃ Sn(L) (R = Me 1 ; Bu 2 ; Ph 3 ; PhCH₂ 4 ) and R₂Sn(L)₂ (R = CH₃ 5 ; Ph 6 ; PhCH₂ 7 ; Bu 8 ) have been synthesized. All complexes 1–8 were characterized by elemental analysis, IR,¹H, ¹³ C, and ¹¹⁹Sn NMR spectra. Among these, complexes 1 , 3 , 4 , and 7 were also determined by X‐ray crystallography. The tin atoms of complexes 1 , 3 , and 4 are all penta‐coordinated and the geometries at tin atoms of complexes 3 and 4 are distorted trigonal–bipyramidal. Interestingly, complex 1 has formed a 1D polymeric chain through Sn and N intermolecular interactions. The tin atom of complex 7 is hexa‐coordinated and its geometry is distorted octahedral. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:353–364, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20215     

Syntheses and spectroscopic investigation of some cyclophosphazanes: Analysis of pseudo‐triplet splitting

Some new phosphoramidates, 1–3 , and the corresponding cyclophosphazanes, 4–6 , with formula Cl₂P(p‐NHC₆H₄CH₃) 1 , Cl₂P(O)(p‐NHC₆H₄NO₂) 2 , (CH₃)₂NP(O)Cl(p‐NHC₆H₄CH₃) 3 , [ClP(p‐NC₆H₄CH₃)]₂ 4 , [ClP(O)(p‐NC₆H₄NO₂)]₂ 5 , and [(CH₃)₂NP(O)(p‐NC₆H₄CH₃)]₂ 6 were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR, mass spectroscopy, and elemental analysis. A pseudo‐triplet signal was observed in the ¹H NMR spectrum of molecule 6 for the N(CH₃)₂ protons. The A₆A′ ₆X₂ spin system was suggested for the pseudo‐triplet pattern of ³J_PNCH coupling in this molecule. Ab initio calculations were performed at the HF and B3LYP levels of theory with 6‐311G^** standard basis set on the geometry of compound 6 . Also, the NMR chemical shift calculations were done to compare the computed results with the experimental ones. The calculated results are in good agreement with experimental data. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:337–343, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20229     

Synthesis and characterization of dimeric organotin compounds {[(ArCH2)2 Sn(2‐quin)]2O}2 and crystal structure of {[(2‐ClC6 H4CH2)2Sn(2‐quin)]2O}2

Ten new dimeric organotin compounds {[(ArCH₂)₂ Sn(2‐quin)]₂O}₂ (Ar = Ph 1 , 2‐ClC₆H₄ 2 , 3‐ClC₆H₄ 3 , 4‐ClC₆H₄ 4 , 2‐FC₆H₄ 5 , 3‐FC₆H₄ 6 , 4‐FC₆H₄ 7 , 4‐BrC₆H₄ 8 , 4‐CNC₆H₄ 9 , 2,4‐Cl₂C₆H₃ 10 ) have been synthesized by dealkylation reactions of 2‐quinH with [(ArCH₂)₃Sn]₂O, and their structures have been characterized by elemental analysis, IR and NMR (¹}H, ¹³C, ¹¹⁹Sn) spectroscopies. The structures of {[(2‐ClC₆H₄CH₂)₂Sn(2‐quin)]₂O}₂ 2 have been determined by X‐ray diffraction. Studies show that compound 2 has a tetranuclear, centrosymmetric dimeric structure, with the endo‐cyclic tin atom five‐coordinated and the exo‐cyclic tin atom six coordinated. Studies also show that the nitrogen atoms of the 2‐quin ligand are coordinating to the tin atom for all the ten compounds. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:152–159, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20194     

Synthesis and properties of poly(phenylacetylenes) having two polar groups or one cyclic polar group on the phenyl ring

Phenylacetylene (PA) derivatives having two polar groups (ester, 2a – d ; amide, 4) or one cyclic polar group (imide, 5a – c ) were polymerized using (nbd)Rh⁺[(η⁶‐C₆H₅)B^?(C₆H₅)₃] catalyst to afford high molecular weight polymers (～1 × 10⁶ – 4 × 10⁶). The hydrolysis of ester‐containing poly(PA), poly( 2a) , provided poly(3,4‐dicarboxyPA) [poly ( 3 )], which could not be obtained directly by the polymerization of the corresponding monomer. The solubility properties of the present polymers were different from those of poly(PA) having no polar group; that is, poly( 2a )–poly( 2d ) dissolved in ethyl acetate and poly( 4 ) dissolved in N,N‐dimethylformamide, while poly(PA) was insoluble in such solvents. Ester‐group‐containing polymers [poly( 2a )–poly( 2d )] afforded free‐standing membranes by casting from THF solutions. The membrane of poly( 2a ) showed high carbon dioxide permselectivity against nitrogen (PCO₂/PN₂ = 62). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5943–5953, 2006     

Diorganotin(IV) complexes of 2,5‐dithiobiurea (H2dtbu). The crystal structures of Me2Sn(dtbu) and Ph2Sn(dtbu)

The diorganotin(IV) complexes, R₂Sn(dtbu) (R = Me 1 , n‐Bu 2 , Ph 3 , PhCH₂ 4 ; H₂dtbu = 2,5‐dithiobiurea), have been synthesized and characterized by IR, ¹H, and ¹¹⁹Sn NMR spectroscopy. The structures of 1 and 3 have been determined by X‐ray crystallography. Crystal structures show that both complexes 1 and 3 consist of molecules in which the bideprotonated ligand is N,S,S‐bonded, and the tin atom exhibits distorted pentacoordination with small differences between the methyl and phenyl derivatives in bond distances and bond angles. The unusual coordination mode of the dtbu²⁻ anion creates four‐ and five‐membered chelate rings. Moreover, the packing of complexes 1 and 3 are stabilized by the hydrogen bonding. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:93–98, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20173     

One‐pot synthesis of aryl and heteroaroyl‐substituted hydroxypyrazolines from the reactions of β‐alkoxyvinyl trichloromethyl ketones with heteroarylhydrazides

The one‐step regiospecific synthesis of a novel series of 10 trichloromethyl‐, aryl‐, and heteroaroyl‐substituted 5‐hydroxy‐2‐pyrazolines affords 1‐(2‐thenoyl)‐, 1‐(2‐furoyl)‐, and 1‐(isonicotinoyl)‐3‐aryl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐pyrazoles in 63–92% yields from the cyclocondensation reactions of 1,1,1‐trichloro‐4‐methoxy‐4‐aryl‐3‐buten‐2‐ones (where aryl substituents are –C₆H₅, 4‐CH₃C₆H₄, 4‐OCH₃C₆H₄, 4‐FC₆H₄, 4‐ClC₆H₄, 4‐BrC₆H₄) with 2‐thiophenecarboxylic hydrazide, furoic hydrazide, and isonicotinic acid hydrazide, respectively. Dehydration reaction of two 2‐pyrazolines with P₂O₅ furnished the corresponding 1H‐pyrazoles in low yields (21–29%). © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:685–691, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20261     

Synthesis of novel zirconium complexes bearing mono‐Cp and tridentate Schiff base [ONO] ligands and their catalytic activities for olefin polymerization

A series of novel zirconium complexes {R²Cp[2‐R¹‐6‐(2‐CH₃OC₆H₄N?CH)C₆H₃O]ZrCl₂ ( 1 , R¹ = H, R² = H, 2 : R¹ = CH₃, R² = H; 3 , R¹ = ^tBu, R² = H; 4 , R¹ = H, R² = CH₃; 5 , R¹ = H, R² = n‐Bu)} bearing mono‐Cp and tridentate Schiff base [ONO] ligands are prepared by the reaction of corresponding lithium salt of Schiff base ligands with R²CpZrCl₃·DME. All complexes were well characterized by ¹H NMR, MS, IR and elemental analysis. The molecular structure of complex 1 was further confirmed by X‐ray diffraction study, where the bond angle of Cl? Zr? Cl is extremely wide [151.71(3)°]. A nine‐membered zirconoxacycle complex Cp(O? 2? C₆H₄N?CHC₆H₄‐2? O)ZrCl₂ ( 6 ) can be obtained by an intramolecular elimination of CH₃Cl from complex 1 or by the reaction of CpZrCl₃·DME with dilithium salt of ligand. When activated by excess methylaluminoxane (MAO), complexes 1–6 exhibit high catalytic activities for ethylene polymerization. The influence of polymerization temperature on the activities of ethylene polymerization is investigated, and these complexes show high thermal stability. Complex 6 is also active for the copolymerization of ethylene and 1‐hexene with low 1‐hexene incorporation ability (1.10%). Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis and structures of cycloalkylidene‐bridged mixed cyclopentadienyl‐indenyl tetracarbonyl diruthenium complexes

A series of cycloalkylidene‐bridged mixed cyclopentadienyl‐indenyl tetracarbonyl diruthenium complexes (η⁵:η⁵‐RC₅H₃CR′₂C₉H₆)Ru₂(CO)₂(µ‐CO)₂ [R = H, R′, R′ = Me₂ (1), (CH₂)₄ (2), (CH₂)₅ (3), (CH₂)₆ (4); R = ^tBu, R′, R′ = Me₂ (5), (CH₂)₄ (6), (CH₂)₅ (7)] have been synthesized by reactions of the corresponding ligands RC₅H₄CR′₂C₉H₇ with Ru₃(CO)₁₂ in refluxing xylene. The molecular structures of 2, 6 and 7 have been determined by X‐ray diffraction. Copyright © 2006 John Wiley & Sons, Ltd.     

A new synthetic route to cyclophosphadithiatriazenes: synthesis and X‐ray structural characterization of the first spirocycle containing thiadiazaphosphetidine and phosphadithiatriazene heterocycles

The phosphetidine 2,4‐Di‐tert‐butyl‐3‐chloro‐1λ⁶‐thia‐2,4‐diaza‐3‐phosphetidine‐1,1‐dioxide, O₂S (^tBuN)₂PCl, reacts with tetrasulfur tetranitride, S₄N₄, in benzene under reflux to afford the novel 4,6‐spirocycle in moderate yield. The deep‐blue crystals of the spirocycle are airstable and high melting in nature. The spiro phosphorus atom subtends a four‐membered P^VS^VIN₂ ring which is saturated, and a six‐membered P^VS N₃ ring which is unsaturated. The single‐crystal X‐ray structure of this first example of the spirocycle reveals a planar PSN₂ ring and a puckered PS₂N₃ ring and the molecule is symmetric in nature. Copyright © 2006 John Wiley & Sons, Ltd.     

Syntheses of symmetric and unsymmetric 2,6‐bis(phosphino)phenols

Compounds bearing the structural motif of 2,6‐bis(phosphino)phenol have been synthesized via two general methods. Double lithium‐halogen exchange occurred in low‐temperature reactions of O‐protected (by methyl‐ or tetrahydropyranyl groups) 2,6‐dibromo‐4‐methylphenol derivatives with BuLi (2 equivalents); quenching the reaction mixtures with chlorophosphines ClPR₂ (R = Ph, ⁱPr) and corresponding O‐deprotection yielded symmetrically substituted 2,6‐bis(phosphino)phenols. Sequential incorporation of  PR₂ functionalities was accomplished via single lithium‐halogen exchange (1 eq. of BuLi) of tetrahydropyranyl‐protected 2,6‐dibromo‐4‐methylphenol followed by ClPR₂ quenches, thus enabling the syntheses of unsymmetric 2,6‐bis(phosphino)phenols. Such compounds were also obtained via sequential ortho‐lithiations of tetrahydropyranyl‐protected 4‐tert‐but ylphenol, followed by ClPR₂ quenches. All of the new compounds have been characterized by spectrometric methods (¹H and ³¹P NMR, and mass spectrometry). In addition, two of the compounds, 1‐(diphenylphosphino)‐3‐(diphenylphosphoryl)‐2‐methoxy‐5‐methylbenzene ( 3a‐ox ) and 1,3‐bis(diphenylphosphino)‐2‐methoxy‐5‐methylbenzene ( 6a ) have also been characterized via single crystal X‐ray diffraction experiments. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:656–663, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20251     

Synthesis and characterization of Mannich base monophenolate lanthanide complexes and their application in ring‐opening polymerization of ε‐caprolactone

A series of Mannich base monophenol ligands [2,4‐^tBu₂‐6‐CH₂NMe₂‐PhOH ( HA ), 2,4‐^tBu₂‐6‐CH₂NEt₂‐PhOH ( HB ), 2,4‐^tBu₂‐6‐CH₂Py‐PhOH ( HC ), 2‐^tBu‐4‐Me‐6‐CH₂Py‐PhOH ( HD ), 4‐^tBu‐2,6‐(CH₂Py)₂‐PhOH ( HE )] were synthesized by Mannich reaction using phenol and formaldehyde reacting with secondary amine. A series of homoleptic lanthanide complexes [LaA₃ ( 1 ), GdA₃ ( 2 ), LaB₃ ( 3 ), GdB₃ ( 4 ), LaC₃ ( 5 ), GdC₃ ( 6 ), LaD₃ ( 7 ), GdD₃ ( 8 ), LaE₃ ( 9 ), GdE₃ ( 10 )] were prepared by amine elimination reactions of the ligands with Ln[N(SiMe₃)₂]₃ (Ln = La, Gd). Complexes 1 , 3 , 5 , 7 and 9 were all characterized using NMR spectra, and the structures of complexes 3 and 5 were determined using single‐crystal X‐ray diffraction. Complexes 3 and 5 are isostructural, and the lanthanum center exhibits a distorted octahedral geometry, in which the O(1), O(2) and O(3) atoms occupy three positions and N(1), N(2) and N(3) atoms occupy the other three positions. All complexes were characterized using elemental analysis and infrared spectra. The catalytic properties of complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 for the ring‐opening polymerization of ε‐caprolactone were studied, and the results show that all complexes are efficient initiators for this ring‐opening polymerization reaction. Copyright © 2016 John Wiley & Sons, Ltd.     

Syntheses,characterizations, and crystal structures of organotin(IV) chloride complexes with 4,4′‐bipyridine

The organotin(IV) chlorides R_nSnCl_4−n (n = 3, R = Ph, PhCH₂, n−Bu; and n =2, R = n−Bu, Ph, PhCH₂) react with 4,4′‐bipyridine (4′4‐bpy) to give [(Ph₃SnCl)₂(4,4′‐bpy)_1.5(C₆H₆)_0.5] ( 1 ), [(PhCH₂)₃‐ SnCl]₂ (4,4′‐bpy) ( 2 ), [(n−Bu)₃SnCl]₂(4,4′‐bpy) ( 3 ), [(n−Bu)₂SnCl₂(4,4′‐bpy)] ( 4 ), [Ph₂SnCl₂(4,4′‐bpy)] ( 5 ), and [(PhCH₂)₂SnCl₂(4,4′‐bpy)] ( 6 ). The new complexes have been characterized by elemental analyses, IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopy. The structures of ( 1 ), ( 2 ), ( 4 ), and ( 6 ) have been determined by X‐ray crystallography. Crystal structures of ( 1 ) and ( 2 ) show that the coordination number of tin is five. In complex ( 1 ), two different molecules exist: one is a binuclear molecule bridged by 4,4′‐bpy and another is a mononuclear one, only one N of 4,4′‐bpy coordinate to tin. Complex ( 2 ) contains an infinite 1‐D polymeric binuclear chain by weak Sn…Cl intermolecular interactions with neighboring molecules. In the complexes ( 4 ) and ( 6 ), the tin is six‐coordinate, and the 4,4′‐bpy moieties bridge adjacent dialkyltin(IV)dichloride molecules to form a linear chain. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:338–346, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20016     

Synthesis and properties of azobenzene‐containing poly(1‐alkyne)s with different functional pendant groups

1‐Alkynes containing azobenzene mesogenic moieties [HC?C(CH₂)₉? O? ph? N?N? ph? O? R; R = ethyl ( 1 ), octyl ( 2 ), decyl ( 3 ), (S)‐2‐methylbutyl ( 4 ), or (S)‐1‐ethoxy‐1‐oxopropan‐2‐yl ( 5 ); ph = 1,4‐phenyl] were synthesized and polymerized in the presence of a Rh catalyst {(nbd)Rh⁺[B(C₆H5)₄]^?; nbd = 2,5‐norbornadiene} to yield a series of liquid‐crystalline polymers in high yields (e.g., >75%). These polymers had moderate molecular weights (number‐average molecular weight ≥ 12,000), high cis contents in the main chain (up to 83%), good thermal stability, and good solubility in common organic solvents, such as tetrahydrofuran, chloroform, and dichloromethane. These polymers were thoroughly characterized by a combination of infrared, nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, polarized optical microscopy, and two‐dimensional wide‐angle X‐ray diffraction techniques. The liquid‐crystalline behavior of these polymers was dependent on the tail group attached to the azobenzene structure. Poly‐ 1 , which had the shortest tail group, that is, an ethyl group, showed a smectic A mesophase, whereas poly‐ 2 , poly‐ 3 , and poly‐ 5 , which had longer or chiral tail groups, formed smectic C mesophases, and poly‐ 4 , which had another chiral group attached to the azobenzene structure, showed a chiral smectic C mesophase in both the heating and cooling processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4532–4545, 2006     

Nickel (II) complexes supported by a fluorinated β‐diketiminate backbone ligand: synthesis,catalytic activity toward norbornene polymerization,and the oxygenated species

The reaction of the lithium salt of backbone fluorinated β‐diketiminate ligands, ArNC(CF₃)CHC(CF₃) NArLi, with trans‐[NiCl(Ph)(PPh₃)₂] gives nickel (II) complexes, ArNC(CF₃)CHC(CF₃)NAr(Ph) (PPh₃)Ni (Ar = 2, 6‐Me₂C₆H₃: 1 ; 2, 6‐ⁱPr₂C₆H₃: 2 ). When activated by methylaluminoxane (MAO), both complexes polymerize norbornene rapidly via a vinyl‐type polymerization mechanism. Treatment of nickel complex 1 with oxygen gives rise to intramolecular aerobic hydroxylation. The oxygenated species 3 was characterized by X‐ray crystallography. Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis and characterization of novel chelated dimethylamino lithium arylamide dimers: molecular structure of [1‐LiNPhCHPhCH2‐2‐NMe2C6H4]2

The reaction of 1‐NHPhCHPh‐2‐NMe₂C₆H₄ ( 1 ) and 1‐NHPhCHPhCH₂‐2‐NMe₂C₆H₄ ( 2 ) with n‐BuLi in diethyl ether gave the solvent‐free chelated dimethylamino lithium amides [1‐LiNPhCHPh‐2‐NMe₂C₆H₄]₂ ( 3 ) and [1‐LiNPhCHPhCH₂‐2‐NMe₂C₆H₄]₂ ( 4 ). The lithium amides 3 and 4 were characterized by ¹H, ⁷Li, and ¹³C NMR spectroscopy. A crystal structure determination was carried out on 4 , which is the first example of a structurally characterized solvent‐free dimeric chelated dimethylamino lithium arylamide with three‐coordinate lithium centers that contains a seven‐membered chelate ring. Copyright © 2003 John Wiley & Sons, Ltd.     

Syntheses of some new 1H‐pyrazole,pyridazin‐3(2H)‐one,and oxazin‐4‐one derivatives

The new 1H‐pyrazole‐3‐carboxylic acid 2 , pyridazin‐3(2H)‐one 3 , and their various derivatives were prepared by the reactions of the 4‐benzoyl‐5‐phenyl‐2,3‐dihydro‐2,3‐furandione 1 and 2,5‐dichlorophenylhydrazine. Pyrazolo[3,4‐d]pyridazine 7 was obtained from cyclization of the pyrazole‐3‐carboxylic acid 2 with 2,5‐dichlorophenylhydrazine. The reaction of 1 and pyrazole‐3‐carbonitriles 6 gave the new oxazin‐4‐one 9 derivatives. The structures of compounds were characterized on the basis of elemental analyses, mass, IR, ¹H, and ¹³C NMR spectra. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:8–12, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20170     

1H, 13C and 15N NMR spectroscopic,x‐ray structural and ab initio/HF studies on nitramino and N‐alkylamino‐4‐nitro derivatives of pyridine N‐oxides and pyridines

The ¹H, ¹³C and ¹⁵N NMR spectra in DMSO‐d₆ were measured for eight nitraminopyridine N‐oxides, ten 4‐nitropyridine N‐oxides, four 2‐nitraminopyridines and five 4‐nitropyridines. Their chemical shift assignments are based on PFG ¹H,X (X = ¹³C and ¹⁵N) HMQC and HMBC experiments. The relative energies for the tautomers of two nitraminopyridine N‐oxides were determined by ab initio HF/6–311G** calculations. A single‐crystal x‐ray structural analysis was made for 4‐methyl‐2‐nitraminopyridine: C₆H₇O₂N₃, M = 153.15, triclinic, space group P‐1 (No. 2), a = 7.0275(4), b = 6.8034(3), c = 8.6086(5) Å, α = 103.620(2), β = 90.309(2), γ = 122.215(3)°, V = 334.11(3) ų, Z = 2. Copyright © 2003 John Wiley & Sons, Ltd.     

Syntheses,Structures, and Properties of Phosphorescent Iridium(III) Complexes Containing N‐Heterocyclic Carbene Ligands

The organic salts 1‐(2‐pyridylmethyl)‐3‐alkylbenzimidazolium halide (pm‐RbH ⁺X⁻) and 1‐(2‐pyridylmethyl)‐3‐alkylimidazolium halide (pm‐R′iH ⁺X′⁻) were prepared (where R = 4‐, 3‐, 2‐fluorobenzyl ( 4f , 3f , and 2f , respectively), 4‐, 3‐, 2‐chlorobenzyl ( 4c , 3c , and 2c , respectively); 4‐methoxybenzyl (4mo); 2,3,4,5,6‐pentafluorobenzyl (f₅); benzyl (b); and methyl (m)); X = Cl and Br; R′ = benzyl (b) and methyl (m); and X′ = Cl and I. From these salts, heteroleptic Ir(III ) complexes containing one N ‐heterocyclic carbene (NHC ) ligand [Ir(κ²‐ppy)₂(κ²‐(pm‐Rb))]PF₆ (R = 4f, 1 (PF₆ ); 3f, 2 (PF₆ ); 2f, 3 (PF₆ ); f₅b, 4 (PF₆ ); 4c, 5 (PF₆ ); 3c, 6 (PF₆ ); 2c, 7 (PF₆ ); 4mo, 8 (PF₆ ); b, 9 (PF₆ ); m, 10 (PF₆ )) and [Ir(κ²‐ppy)₂(κ²‐(pm‐R′i))]PF₆ (R = b, 11 (PF₆ ); m, 12 (PF₆ )), were synthesized, and the crystal structures of 1 (PF₆ ), 2 (PF₆ ), 3 (PF₆ ), 5 (PF₆ ), 6 (PF₆ ), 7 (PF₆ ), 9 (PF₆ ), 10 (PF₆ ), and 12 (PF₆ ) were determined by X‐ray diffraction. The neutral NHC ligands 1‐(2‐pyridylmethyl)‐3‐alkylbenzimidazolin‐2‐ylidene (pm‐Rb) and 1‐(2‐pyridylmethyl)‐3‐alkylimidazolin‐2‐ylidene (pm‐R′i) of all cations were found to be involved in the intermolecular π−π stacking interactions with the surrounding cations in the solid state, thereby probably influencing the photophysical behavior in the solid state and in solution. The absorption and emission properties of all the complexes show only small variations.     

Synthesis and structure of 1‐phospholyl‐ and di(1‐phospholyl)acetylenes and the corresponding sulfides

The acetylenes possessing one and two 1‐phospholyl groups were synthesized by reaction of the alkynyl Grignard reagents with the 1‐chlorophosphole and converted to the corresponding phosphole sulfides. Reaction of the 1‐phenylethynylphosphole sulfide with CpCo(CO)₂ resulted in η⁴‐complexation on the phosphole moiety. The structures of the di(1‐phospholyl)acetylene disulfide and the [η⁴‐(1‐phenylethynylphosphole sulfide)]cobalt(I) complex were characterized by X‐ray crystallography. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:344–349, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20230     

Binuclear dichlorido(η6‐p‐cymene)ruthenium(II) complexes with bis(nicotinate)‐ and bis(isonicotinate)‐polyethylene glycol ester ligands

Neutral binuclear ruthenium complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 of the general formula [{RuCl₂(η⁶‐p‐cym)}₂ μ‐(N^∩N)] (N^∩N = bis(nicotinate)‐ and bis(isonicotinate)‐polyethylene glycol esters: (3‐py)COO(CH₂CH₂O)_nCO(3‐py) and (4‐py)COO(CH₂CH₂O)_nCO(4‐py), n =1–4), as well as mononuclear [RuCl₂(η⁶‐p‐cym)((3‐py)COO(CH₂CH₂OCH₃)‐κN)], complex 9 , were synthesized and characterized using elemental analysis and electrospray ionization high‐resolution mass spectrometry, infrared, ¹H NMR and ¹³C NMR spectroscopies. Stability of the binuclear complexes in the presence of dimethylsulfoxide was studied. Furthermore, formation of a cationic complex containing bridging pyridine‐based bidentate ligand was monitored using ¹H NMR spectroscopy. Ligand precursors, polyethylene glycol esters of nicotinic ( L1 · 2HCl– L4 · 2HCl and L9 · HCl) and isonicotinic acid dihydrochlorides ( L5 · 2HCl– L8 · 2HCl), binuclear ruthenium(II) complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and mononuclear complex 9 were tested for in vitro cytotoxicity against 518A2 (melanoma), 8505C (anaplastic thyroid cancer), A253 (head and neck tumour), MCF‐7 (breast tumour) and SW480 (colon carcinoma) cell lines. Copyright © 2014 John Wiley & Sons, Ltd.