X2 Complexes Research Articles

Complexes of Group IIb Metals With Dithiooxamides V‐Vibrational Spectra And Thermal Analysis of the CdLX2 Complexes

AbstractIn acid media, CdX2 forms non‐electrolyte CdLX2 (L=DTO, NN′DMDTO, TMDTO; X=Cl, Br, I) complexes with dithiooxamides. The ligands act as bidentates with S,S coordination.A thorough vibrational analysis (i.r. and Raman) has been performed for the Cd(H2NCSCSNH2)X2 (X=Cl, Br, I), the Cd(CH3NHCSCSNHCH3)X2 (X=Br, I) and the Cd[(CH3)2NCSCSN(CH3)2]X2 (X=Cl, Br, I) complexes, by NH/ND and CH3/CD3 isotopic substitution. Stereochemistries varying from tetrahedral to octahedral structures are proposed based on spectroscopic evidence and the positions of the metal‐ligand vibrations can be explained in terms of the HSAB principle.The thermal behaviour of the complexes has been studied, using isothermal as well as non‐isothermal techniques.

Coordination of Pyridine-Substituted Pyrazoles and Their Influence on the Spin State of Iron(II)

Iron(II) and nickel(II) [MN6]X2 type complexes have been prepared from 2-(pyrazol-1-yl]pyridine (1pp), 2-(pyrazol-1-yl) imidazoline (pi), 2- (pyrazol-3-yl)pyridine (3pp) and 2,6-bis(pyrazol-3-yl)pyridine ( bpp ). Variable-temperature magnetic and Mossbauer spectral studies establish that [Fe(1pp)3]X2 is low spin and [Fe(pi)3]X2 is high spin over an extended temperature range, while both [Fe(3pp)3]X2 and [Fe( bpp )2]X2 undergo temperature-induced low-spin ↔ high-spin transitions. The nature of the transition depends on the extent of hydration and for salts of both cations the singlet state is generally stabilized as the extent of hydration increases. Hydrogen bonding effects are believed to be responsible for this. For anhydrous [Fe( bpp )2] [BF4]2 the transition is discontinuous and associated with hysteresis with Tc ↓ 173 K for decreasing temperature and Tc ↑ 183 K for increasing temperatures. The transition to the singlet state species is complete at low temperatures provided that the cooling rate is relatively slow. Rapid cooling to 77 K results in the trapping of a fraction of metastable quintet state species. For all other species containing either [Fe(3pp)3]2+ or [Fe( bpp )2]2+ the spin transition is continuous. Spectral data for [NiN6]X2 complexes establish an order of field strengths for the ligands pi < 3pp < 1pp < bpp , which, for the bidentate species only, is consistent with the observed electronic properties of the corresponding [FeN6]X2 complexes.

Studies on syntheses, reactivity and antibacterial activity of nickel(II) complexes of some N-S donors

Square-planar and octahedral complexes of some selected bidentate N-S donor (HL) ring-substituted 4-phenylthiosemicarbazides possessing antibacterial activity have been prepared and characterized. Transformation of the red square-planar [Ni(HL)2]X2 complexes to the corresponding blue [Ni(HL)2(H2O)2]X2 octahedral complexes have been studied. The reactivity of the red square-planar complexes towards various monodentate Lewis base (B) was also examined, and octahedral complexes of the type [Ni(L)2B2] and [Ni(HL)B2]X2 were characterized. Thein vitro antibacterial activity of several of the red and blue complexes is higher than that of the unbound donors.

The Uv‐Vis Spectra of the M(LH2)2X2 Complexes with Planar Dithiooxamides. M=Ni,Pd,Pt; X=Cl,Br,I

AbstractThe electronic spectra of the M(LH2)2X2 complexes with planar dithiooxamides have been recorded in KX matrices. The relative positions of the absorption bands and the characteristic shifts on metal and ligand substitution are used to assign the electronic transitions.

Thermal Studies of 1,2-Propanediamine Complexes of Zinc(II) and Cadmium(II) in the Solid Phase

Abstract [ML3]X2·nH2O, where M=ZnII and CdII; L=1,2-propanediamine; X=Cl−, Br−, 0.5SO42−, and 0.5SeO42− and n=1, 1.5, and 2, have been synthesized and their thermal investigations carried out. ZnL1.5Cl2, CdL1.5X2 (X=Cl− and Br−), and CdLX2 (X=Cl−, 0.5SO42−, and 0.5SeO42−) have been synthesized pyrolytically in solid state from their parent diamine complexes. These ML1.5X2 complexes are expected to exist as [ML3][MX4]. Only [CdL3][CdBr4] species has been synthesized from solution. Syntheses of ZnLCl2, CdLCl2, and CdLBr2 from solution have also been reported. IR spectra suggest that symmetry of the chelate ring in mono (diamine) complexes is lowered in comparison to the other complexes. ML1.5Cl2 show isomorphism with each other. Thermal stability sequence of [ML3]X2 (X=Br−, 0.5SO42− and 0.5SeO42−) is SO42−<SeO42−≤Br−. [ZnL3]X2 and ZnLX2 appear thermally more stable than those of cadmium complexes. All these complexes are thermally less stable than those of 1,2-ethanediamine complexes reported by us earlier.

Mixed halodicyclopentadienyl-niobium(V) and -tantalum(V)

Oxidation of (η 5-C 5H 5) 2MCl (M = Nb, Ta) with 1 mol of Cl 2, Br 2 or I 2 gives (η 5-C 5H 5) 2MClX 2 whereas the reaction with an excess of the halogen gives the cationic complexes [η 5-C 5H 5) 2MClX] + X 3 − (X = Br, I). Similar oxidation of (η 5-C 5H 5) 2MCl 2 with 0.5 mol of halogen gives (η 5-C 5H 5) 2MCl 2X complexes, but if the halogen is used in excess cationic [η 5-C 5H 5) 2MCl 2] + X 3 − (X = Br, I; M = Ta and X = I, M = Nb) are obtained. All these complexes can also be obtained simultaneously by oxidizing (η 5-C 5H 5) 4M 2Cl 3, and the separation is fairly easy in most cases. Conductivity and IR and NMR data are discussed.

Iron(III) complexes of sodium 2-pyridinecarboxaldehyde dithiocarbazonate, a possible chelating agent for the treatment of iron overload

The 1:2 complexes of iron(III) with sodium 2-pyridinecarboxaldehyde dithiocarbazonate of the formula Fe(PD) 2X (where PD is 2-pyridinecarboxaldehyde dithiocarbazonate anion, and X − = Cl −, NO 3 −, N 3 − and NCS −) have been prepared by interaction of iron(III) ions with NaPD (1:2), in the presence of an appropriate anion. They show molar conductance values of 33.0 to 55.2 mhos cm 2 mol −1 in DMF solution. These data indicate that the anions of FE(PD) 2X are associated in the first coordination sphere of Fe(III) to a different extent in DMF solution. The ultraviolet-visible absorption spectral data of FE(PD) 2X in DMF solution also support the different extent of coordination of anions to Fe(III). The Fe(PD) 2X complexes in the solid state have low spin iron(III) with μ eff values varying from 1.95 to 2.35 BM. The EPR data of the iron(III) complexes in frozen DMF also support their low-spin nature. These data also show that all complexes have rhombic symmetry except the azide complexes which have axial symmetry. The EPR and infrared spectral data of iron(III) complexes also suggest that the anions of these complexes are associated in the first coordination sphere of iron(III) in the solid state. The association of anions in the Fe(PD) 2X complexes may suggest their geometry to be capped octahedron or pentagonal bipyramid. It has been suggested that one of the most important factors for efficiently removing iron from iron loaded mice is the formation of kinetically inert low-spin iron(III) complexes between iron(III) ions and tridentate chelating agents in the ratio of 1:2.

Ruthenium carbonyl complexes. III. Peparations, properties and structures of Dicarbonyl- and Monocarbonyl-(2,2':6',2''-terpyridyl)ruthenium(II) complexes

Reaction of 2,2':6',2''-terpyridyl (tpy) with ruthenium dicarbonyl dihalides yields the complexes Ru(CO)2X2(tpy) (X = Br or Cl), which can be protonated giving [Ru(CO)2X2(tpyH)]ClO4. Crystal structures of the two forms (red and yellow) of Ru(CO)2Br2(tpy) show each to have octahedral stereo-chemistry with cis-carbonyls, trans-bromines, and bidentate tpy. Treatment of Ru(CO)2X2(tpy) complexes with trimethylamine N-oxide in dichloromethane at room temperature gives cis-Ru(CO)X2(tpy) complexes. The presence of cis halogens and tridentate terpyridyl in the chloro complex has been established by X-ray crystallography. Reaction of terpyridyl with ruthenium trichloride in dimethylformamide yields trans-Ru(CO)Cl2(tpy), the crystal structure of which has been determined.

The infrared spectra of imidazole complexes of platinum(II) halides and nitrite

The i.r. spectra (4000-90 cm−1) of the [Pt(Him)4]X2 complexes (Him = imidazole, X = Cl, Br or I) andcis- andtrans-[Pt(Him)2X2] (X = Cl, Br, I or NO2) and their D3-labelled analogues have been determined. The distinction between the ring and C-H (or N-H) modes of imidazole is based on the relative shifts which these bands undergo on D3-labelling. Assignments, based on the effects of imidazole deuteriation and halide substitution, are provided for the v(Pt-Him) and v(Pt-X) modes.

Silver(I) complexes of 4,6-dimethylpyrimidine-2(1H)-thione

The following silver(I) complexes of 4,6-dimethylpyrimidine-2(1H)-thione (HL) have been prepared and investigated by conductometric, infrared, and Raman methods: Ag(HL)X (X = Cl, Br, I, SCN), Ag(HL)2X (X = Cl, Br, I, NO3 (MeOH), ClO4 (0.25CHCl3), BF4 (0.25CHCl3)), AgmXn(H2L)n–m (X = Cl: m = 6, n = 11; Br: m = 2, n = 3; I: m = 5, n = 7), AgL, AgL•Ag(HL)NO3, AgL•[Ag(HL)X]2 (X = ClO4, BF4). The HL acts as N,S-chelating ligand in the Ag(HL)X and Ag(HL)2X (X = NO3,ClO4, BF4) complexes and partially in the Ag(HL)2X (X = Cl, Br, I) complexes in which the halide ion is still coordinated. In the AgmXn(H2L)n–m complexes the H2L+ ion is at least partially S-coordinated to some silver ions. In AgL, L− acts as tridentate ligand N,N,S-bridging the silver ions. In the AgL•Ag(HL)NO3 complex the nitrate ion is coordinated.

Spectroscopic, magnetic and conductivity measurements of manganese(II) complexes with 2,5-diphenyloxazole

The Mn(PPO)nX2 complexes (where PPO is 2,5-diphenyloxazole, n = 1, 2 or 3 and X = Cl−, Br−, I− or SCN−) have been prepared from the corresponding metal salt with the ligand in methanolic solution or with the molten ligand in the appropriate reactant ratio and studied by chemical analysis, electronic and i.r. spectroscopy, magnetic and molar conductivity values at 25°. The complexes are generally nonconducting in DMF; they are high spin and hexacoordinated. The Mn(PPO)X2 complexes are high polymers with both ligand and anions bridging. The Mn(PPO)2X2 species are polymeric with PPO monodentate N-bonded and halogens and thiocyanates bridging bonded; the Mn(PPO)3X2 derivatives have monodentate N-bonded ligands whereas the halogens and thiocyanates are terminal and bridging, respectively.

ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS‐M(AA)2X2′ CIS‐M(AA)2XY AND CIS‐M(AB)2X2 COMPLEXES. 8. THE CIS‐M(AA)2XY SYSTEM, Y = OPR‐ISO AND 2,6‐(ISO‐PR)2C6H3O

Chemischer InformationsdienstVolume 11, Issue 37 Physical Organic Chemistry ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS-M(AA)2X2′ CIS-M(AA)2XY AND CIS-M(AB)2X2 COMPLEXES. 8. THE CIS-M(AA)2XY SYSTEM, Y = OPR-ISO AND 2,6-(ISO-PR)2C6H3O D. G. BICKLEY, D. G. BICKLEYSearch for more papers by this authorN. SERPONE, N. SERPONESearch for more papers by this author D. G. BICKLEY, D. G. BICKLEYSearch for more papers by this authorN. SERPONE, N. SERPONESearch for more papers by this author First published: September 16, 1980 https://doi.org/10.1002/chin.198037076Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume11, Issue37September 16, 1980 RelatedInformation

A Class of Trinuclear Clusters with Carbonyl Bridging

AbstractThe impetus for this work was the structure of a trinuclear complex with two carbonyl groups showing incipient triple bridging ‐ Cp2Rh3(CO)4−. Its structure, barrier to rotation of one Rh(CO)2− piece vs. the rest of the molecule, and the nature of the bridging carbonyl interaction are analyzed. Isolobal analogies form an interesting connection between this complex and a bridged isomer of the recently synthesized carbene complexes, Cp2Rh2(CO)2CR2, one isomer of Cp2Rh3(CO)3, and hypothetical carbyne complexes Cp2Rh2(CO)2CH+,−. A general bonding model for Cp2Rh2(μ‐CO)2X complexes is constructed. The model, rich in geometrical detail, allows minima for the bridging carbonyl groups bending toward and away from the bonded ligand X.

ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS‐M(AA)2X2, CIS‐M(AA)2XY, AND CIS‐M(AB)2X2 COMPLEXES. 6. BIS(CHELATE)BIS(2,6‐DIISOPROPYLPHENOXY)TITANIUM SYSTEMS (CHELATE = ACETYLACETONATE, 8‐HYDROXYQUINOLINATE, AND 8‐HYDROXYQUINALDINATE)

Chemischer InformationsdienstVolume 10, Issue 45 Physical Organic Chemistry ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS-M(AA)2X2, CIS-M(AA)2XY, AND CIS-M(AB)2X2 COMPLEXES. 6. BIS(CHELATE)BIS(2,6-DIISOPROPYLPHENOXY)TITANIUM SYSTEMS (CHELATE = ACETYLACETONATE, 8-HYDROXYQUINOLINATE, AND 8-HYDROXYQUINALDINATE) D. G. BICKLEY, D. G. BICKLEYSearch for more papers by this authorN. SERPONE, N. SERPONESearch for more papers by this author D. G. BICKLEY, D. G. BICKLEYSearch for more papers by this authorN. SERPONE, N. SERPONESearch for more papers by this author First published: November 6, 1979 https://doi.org/10.1002/chin.197945061AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue45November 6, 1979 RelatedInformation

Configurational rearrangements in cis-M(AA)2X2, cis-M(AA)2XY, and cis-M(AB)2X2 complexes. 6. Bis(chelate)bis(2,6-diisopropylphenoxy)titanium systems (chelate = acetylacetonate, 8-hydroxyquinolinate, and 8-hydroxyquinaldinate)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConfigurational rearrangements in cis-M(AA)2X2, cis-M(AA)2XY, and cis-M(AB)2X2 complexes. 6. Bis(chelate)bis(2,6-diisopropylphenoxy)titanium systems (chelate = acetylacetonate, 8-hydroxyquinolinate, and 8-hydroxyquinaldinate)Douglas G. Bickley and Nick SerponeCite this: Inorg. Chem. 1979, 18, 8, 2200–2204Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://doi.org/10.1021/ic50198a030RIGHTS & PERMISSIONSArticle Views69Altmetric-Citations27LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (639 KB) Get e-Alerts Get e-Alerts

Studies of the Metal Complexes of Cyclohexane Derivatives. VI. The Thermal Transformation of Nickel(II) Complexes of 1,2-Cyclohexanediamine Isomers

Abstract The thermal transformations of the following three types of nickel(II) complexes were investigated by means of TG-DSC analyses: [Ni(t-chxn)2(H2O)2]X2, [Ni(c-chxn)3]X2·nH2O, and [Ni(t-chxn)3]X2·nH2O (X=Cl−, Br−, and NO3−), where c- and t-chxn denote cis- and trans-1,2-cyclohexanediamine respectively. The distorted octahedral [Ni(t-chxn)2(H2O)2]X2 complexes (X=Cl− and Br−) are thermally deaquated to form yellow complexes, which then turn into parental diaquabis-complexes in the air at room temperature. [Ni(t-chxn)2(H2O)2] (NO3)2 undergoes a thermal deaquation-anation reaction. The octahedral tris(c-chxn) complex is converted into a square planar bis(c-chxn) one by the evolution of one molecule of the ligand upon heating, whereas tris(t-chxn) complex became a distorted octahedral bis(t-chxn) one with anion coordination. In this paper, the stereochemical thermal changes of the complexes in the solid state will be discussed with regard to the steric configuration of the ligands.

ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS‐M(AA)2X2, CIS‐M(AA)2XY, AND CIS‐M(AB)2X2 COMPLEXES. 5. THE CIS‐M(AA)2X2 SYSTEM ‐ DIASTEREOTOPIC PROBE ON THE MONODENTATE X LIGANDS

Chemischer InformationsdienstVolume 10, Issue 20 Physical Organic Chemistry ChemInform Abstract: CONFIGURATIONAL REARRANGEMENTS IN CIS-M(AA)2X2, CIS-M(AA)2XY, AND CIS-M(AB)2X2 COMPLEXES. 5. THE CIS-M(AA)2X2 SYSTEM - DIASTEREOTOPIC PROBE ON THE MONODENTATE X LIGANDS N. SERPONE, N. SERPONESearch for more papers by this authorD. G. BICKLEY, D. G. BICKLEYSearch for more papers by this author N. SERPONE, N. SERPONESearch for more papers by this authorD. G. BICKLEY, D. G. BICKLEYSearch for more papers by this author First published: May 15, 1979 https://doi.org/10.1002/chin.197920061Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue20May 15, 1979 RelatedInformation

COORDINATION PROPERTIES OF CONSTRAINED AMINOPHOSPHINES

Abstract The syntheses of mono and disubstituted mononuclear carbonyls of Cr, Mo, W, Fe and Ni with the cage ligand P(NMeCH2)3CMe (2) are reported. The (OC)5CrL and (OC)4FeL complexes are also described where L = As(NMeCH2)3CMe (5). Borane adducts of the complexes of (2) are reported as well as adducts of XP(NMeCH2)3CMe where X = Se and PhN. In the complexes and the selenide the BH3 group is shown from 1H nmr spectroscopy to bind to a nitrogen in a bridging group of the ligand whereas in the phenylimide it binds to the phenylimido nitrogen. Some cis and trans Pt(2)2X2 complexes are also described. The CO stretching frequencies and force constant parameters of the complexes are shown to rise in the ligand order P(NMe2)3 < (2) < (2) · BH3 and this trend is discussed in terms of constraint and inductive effects. The 31P spectra of the compounds are rationalized and 2J31P31P couplings are obtained directly from the 31P spectra of the (2) (OC) x M·(2) · BH3· complexes since the 31P nuclei are chemically nonequ...

ChemInform Abstract: NICKEL(II) AND COPPER(II) COMPLEXES OF 2,5‐DIMETHYL‐1,3,4‐THIADIAZOLE

AbstractDie Niund Cu‐Komplexe (I) und (II) werden durch die Umsetzung entsprechender Metall(I Salze mit dem Titelliganden in Ethanol dargestellt.

ChemInform Abstract: PALLADIUM(II) AND PLATINUM(II) COMPLEXES OF RHODANINE AND 3‐METHYLRHODANINE

AbstractDie Pd‐ und Pt‐Komplexe (I)‐(VI) werden durch stöchiometrische Umsetzung von Pd(II)‐hydroxid oder ‐oxid bzw. Pt(II)‐dihalogenid mit den Titelliganden unter Zugabe von Halogenwasserstoffsäure bzw. Perchlorsäure in geeignetem Lösungsmittel (EtOH, EtOH/Aceton oder Aceton/Methylenchlorid) dargestellt.