铼联吡啶配合物的电喷雾质谱研究

利用电喷雾质谱（ESI-MS）对2，2'-联吡啶-4,4'-二羧酸乙酯与过渡金属铼的 系列配合物[（4,4'-(OOEt)_2-bpy)Re(CO)_3RPF_6] [其中bpy = 2,2'-联吡啶，R = 吡啶、4-甲基吡啶、4-羟基吡啶、4-氨基吡啶、10-（4-甲基吡啶基）吩噻嗪（ py-PTZ）进行分析，研究了配合物及其配体在不同源内CID(in-source collision induced dissociation, in-source CID)的相对稳定性。结果表明，随着源内 CID电压的升高，配合物中的配体R容易脱落并形成稳定的联吡啶三羰配位离子[(4, 4'(COOEt)_2-bpy)Re(CO)_3]~+。配体脱落从易到难的顺序为：吡啶 > 4-甲基吡啶 >-甲基吡啶>4-羟基吡啶>4-氨基吡啶>py-PTZ。     

Oxidorhenium(V) and Rhenium(III) Complexes with m-Terphenyl Isocyanides

Reactions of the sterically encumbered m-terphenyl isocyanides CNAr^Dipp2 (Dipp = 2,6-diisopropylphenyl) and CNAr^Mes2 (Mes = 2,4,6-trimethylphenyl) with (NBu₄)[ReOCl₄] in CH₂Cl₂ form stable complexes of the composition (NBu₄)[ReOCl₃(CNAr^R)] or [ReOCl₃(CNAr^R)₂] depending on the amount of isocyanide added. In the [ReOCl₃(CNAr^R)₂] complexes, cis coordination of the two isocyanides is observed for CNAr^Mes2, while the sterically more demanding CNAr^DIPP2 ligands are found in trans positions. The rhenium(III) species [ReCl₃(PPh₃)(CNAr^Mes2)₂] was obtained from the reaction of [ReOCl₃(PPh₃)₂] and CNAr^Mes2. The ν(CN) IR frequencies measured for the Re^V complexes appear at higher wavenumbers than for the uncoordinated isocyanides, which suggests a low degree of backdonation into anti-bonding orbitals of these ligands.     

Dimeric Rhenium(I) Carbonyl Complexes with Thiosemicarbazone Backbone

Dimeric, neutral rhenium(I) complexes of the composition [Re₂(CO)₆X(L^R)] (X = Cl or Br) are formed when [NEt₄]₂[Re(CO)₃Br₃] or [Re(CO)₃Cl(CH₃CN)₂] react with 2, 2′-dipyridylketone thiosemicarbazones (HL^R, R = H, Ph). The thiosemicarbazones deprotonate during the reaction and connect two tricarbonylrhenium(I) units as formally pentadentate bridging ligands. This results in an extremely rare coordination mode, in which the two nitrogen atoms of the hydrazone unit bind to each one of the rhenium atoms. The bond lengths inside the thiosemicarbazonato backbone reflect a large degree of delocalization of electron density.     

Rhenium(V) Complexes with Bidentate N,O-Donor Imidazole Derivatives

The reaction of a two-fold molar excess of the potential N,O-donor ligand 2-(hydroxymethyl)-1-methylimidazole (Hmi) with trans-[ReOCl₃(PPh₃)₂] led to the isolation of cis-[ReOCl₂(mi)(PPh₃)]. An X-ray structure determination indicated that the complex has distorted octahedral geometry, and that mi coordinates as a bidentate with the alcoholate oxygen trans to the oxo group. A similar reaction with 2-(1-ethyloxomethyl)-1-methylimidazole (eomi), the ethyl substituted analogue of Hmi, led to the formation of the oxo-bridged dinuclear complex [(μ-O){ReOCl₂(eomi)₂}₂]. The ligand eomi coordinates as a monodentate via the imidazole nitrogen, with the "hard" ether oxygen uncoordinated. An X-ray crystal structure indicates that the chlorides are trans to each other in the ReN₂Cl₂ planes, which are orthogonal to the O=Re-O-Re=O backbone.     

Rhenium(I) and Technetium(I) Tricarbonyl Complexes with Phosphoraneimines

[NEt₄]₂[Re(CO)₃Br₃] and [NEt₄]₂[Tc(CO)₃Cl₃] react with trimethylsilyltriphenylphosphoraneimine, Me₃SiNPPh₃, under exchange of the bromo ligands and the formation of cationic [M(CO)₃(HNPPh₃)₃]⁺ complexes (M = Re, Tc). The required protons are abstracted from the solvent CH₂Cl₂. The steric bulk of the organic ligands causes a marked distortion of the established coordination polyhedra from an idealized octahedron with bond angles between neighbouring donor atoms between 81.81(8)° and 96.66(8)°. The reaction of [NEt₄]₂[Re(CO)₃Br₃] with Me₃SiNP(Ph₂)CH₂PPh₂ in CH₂Cl₂ yields the neutral complex [Re(CO)₃Br{HNP(Ph₂)CH₂PPh₂)], which contains a neutral, chelate‐bonded (diphenylphosphinomethyl)diphenylphosphoraneimine ligand. A similar reaction with the bifunctional phosphoraneimine Me₃SiNP(Ph₂)CH₂(Ph₂)PNSiMe₃ gives only small amounts of a binuclear rhenium(I) complex of the composition [{Re(CO)₃Br₂}₂(HNP(Ph₂)CH₂(Ph₂)PNH)]^2‐, whereas the major amount of the bis‐phosphoraneimine undergoes an intramolecular rearrangement to yield [H₂NP(Ph₂)NP(Ph₂)CH₃]Br. An X‐ray structure analysis shows a widespread delocalization of electron density over the central part of the cation.     

环钯化二茂铁亚胺-膦配合物的电喷雾离子阱质谱研究

采用电喷雾离子阱质谱法(ESI-MS)对10种环钯化二茂铁亚胺-膦配合物的质谱特征进行了研究, 获得了其结构碎片信息, 对其质谱裂解途径进行了解析. 结果表明, 在正离子检测方式下可以得到强的准分子离子峰[M-Cl]+簇, 它们的(+) ESI-MSn(n=1~3)质谱主要产生碳-膦键断裂的碎片, 同时也能观察到Pd—P或Pd—C键的断裂, 这些特征为此类化合物及其结构类似物的结构推断提供了依据.     

Oxorhenium(V) Complexes with 1,3,4‐Triphenyl‐1,2,4‐triazol‐5‐ylidene

Reactions of the oxorhenium(V) complexes [ReOX₃(PPh₃)₂] (X = Cl, Br) with the N‐heterocyclic carbene (NHC) 1,3,4‐triphenyl‐1,2,4‐triazol‐5‐ylidene (L^Ph) under mild conditions and in the presence of MeOH or water give [ReOX₂(Y)(PPh₃)(L^Ph)] complexes (X = Cl, Br; Y = OMe, OH). Attempted reactions of the carbene precursor 5‐methoxy‐1,3,4‐triphenyl‐4,5‐dihydro‐1H‐1,2,4‐triazole ( 1 ) with [ReOCl₃(PPh₃)₂] or [NBu₄][ReOCl₄] in boiling xylene resulted in protonation of the intermediately formed carbene and decomposition products such as [HL^Ph][ReOCl₄(OPPh₃)], [HL^Ph][ReOCl₄(OH₂)] or [HL^Ph][ReO₄] were isolated. The neutral [ReOX₂(Y)(PPh₃)(HL^Ph)] complexes are purple, airstable solids. The bulky NHC ligands coordinate monodentate and in cis‐position to PPh₃. The relatively long Re–C bond lengths of approximate 2.1Å indicate metal‐carbon single bonds.     

Electrospray Ionization Mass Spectrometry of Palladium(II) Quinolinylaminophosphonate Complexes

The mass spectrometric behavior of palladium(II) halide complexes of three types of quinolinylaminophosphonates, diethyl and dibutyl esters of [α-anilino-(quinolin-2-yl)methyl]phosphonic (L1, L2), [α-anilino-(quinolin-3-yl)methyl]phosphonic (L3, L4), and [α-(quinolin-3-ylamino)-N-benzyl]phosphonic acid (L5, L6), was investigated under positive ion electrospray ionization conditions. Each type of ligand forms complexes with different metal–ligand interactions. Mononuclear dihalide adducts cis-[Pd(L1/L2)X₂] (1–4) and trans-[Pd(L3/L4)₂X₂] (5–8) as well as dinuclear tetrahalide complexes [Pd₂(L5/L6)₃X₄] (9–12) (X = Cl, Br) are formed by metal bonding either through the quinoline or both the quinoline and amino nitrogen atoms. The sodiated molecule [M + Na]⁺ is observed in the mass spectra of all the complexes, and its abundance as well as the fragmentation pathway depend on the type of the complex. In the cis complexes (1–4) the initial decomposition goes under two fragmentation routes: those in which the sodium molecular adduct sequentially loses halides HX/NaX and those in which this loss is in the competition with the loss of dialkyl phosphite. The predominant pathways for decomposition of trans dihalide (5–8) and tetrahalide (9–12) complexes include three competitive reactions; the loss of halides, dialkyl phosphites and the intact phosphonate ligand molecule and its fragments formed by ester dissociation or complete loss of the phosphonate ester moiety. A series of acetonitrile adducts and cluster ions derived from dimolecular clusters [2M + Na]⁺ were also detected. The most important fragmentation patterns are rationalized and supported by the MS ⁿ studies.     

Meso-四(对烷氧苯基)卟啉金属银配合物的激光解吸电离飞行时间质谱表征

通过激光解吸电离飞行时间质谱对meso-四(对烷氧苯基)卟啉金属银配合物进行了表征.样品溶解在氯仿中,以正离子方式记录谱图,结果发现除了产生目标化合物分子离子峰外,没有任何碎片峰.激光解吸电离飞行时间质谱是表征这种meso-四(对烷氧苯基)卟啉金属银配合物有效的方法.     

Oxorhenium(V) Complexes with Thiosemicarbazones

Neutral oxorhenium(V) complexes with thiosemicarbazones derived from 2‐pyridine formamide, HL¹, are formed when [ReOCl₃(PPh₃)₂] reacts with equimolar amounts of the ligands. Reduction of the metal and the formation of rhenium(III) complexes of the composition [Re(L¹)₂]⁺ occurs when an excess of thiosemicarbazones is used and the reaction is performed in boiling toluene for a prolonged period of time. The thiosemicarbazones deprotonate and act as tridentate ligands as has been confirmed by an X‐ray structure of [ReOCl₂(L^1b)], where HL^1b is 2‐pyridineformamide‐N(4)‐ethylthiosemicarbazone and the ligand occupies the equatorial coordination sphere of the complex together with one of the chloro ligands.     

Tricarbonyl Complexes of Rhenium(I) with Acetylpyridine Benzoylhydrazone and Related Ligands

Novel rhenium(I) tricarbonyl complexes have been prepared by reactions of (Et₄N)₂[Re(CO)₃Br₃] with acetylpyridine benzoylhydrazone, Hapbhyd, di(2‐pyridyl)ketone benzoylhydrazone, Hpy₂bhyd, bis(2‐pyridine)ketone, py₂CO, and pyridinealdehyde terephtalaldehydebishydrazone, pytehyd. The ligands remain protonated when no supporting base is added and the following complexes have been isolated: [Re(CO)₃Br(Hapbhyd)], [Re(CO)₃Br(Hpy₂bhyd‐py, hyd)], [Re(CO)₃Br(Hpy₂bhyd‐py¹, py²)], [Re(CO)₃Br(py₂CO‐N, N)] and [Re(CO)₃Br(pytehyd)]. Addition of triethyl amine results in deprotonation of Hapbhyd and the formation of [Re(CO)₃(OH₂)(apbhyd)], whereas Hpy₂bhyd is hydrolysed and a rhenium complex with the monoanionic bis(2‐pyridyl)hydroxymethanolato ligand, {py₂C(OH)O}^‐, is formed. The same compound, [Re(CO)₃{py₂C(OH)O}], is obtained when triethyl amine and water are added to a mixture of (Et₄N)₂[Re(CO)₃Br₃] and py₂CO. The air‐stable products have been studied by spectroscopic methods and X‐ray crystallography.     

Nitridorhenium(V) Complexes with 1,3,4‐Triphenyl‐1,2,4‐triazol‐5‐ylidene

[ReNCl₂(PPh₃)₂] and [ReNCl₂(PMe₂Ph)₃] react with the N‐heterocyclic carbene (NHC) 1,3,4‐triphenyl‐1,2,4‐triazol‐5‐ylidene (HL^Ph) under formation of the stable rhenium(V) nitrido complex [ReNCl(HL^Ph)(L^Ph)], which contains one of the two NHC ligands with an additional orthometallation. The rhenium atom in the product is five‐coordinate with a distorted square‐pyramidal coordination sphere. The position trans to the nitrido ligand is blocked by one phenyl ring of the monodentate HL^Ph ligand. The Re–C(carbene) bond lengths of 2.072(6) and 2.074(6) Å are comparably long and indicate mainly σ‐bonding between the NHC ligand and the electron deficient d² metal atom. The chloro ligand in [ReNCl(HL^Ph)(L^Ph)] is labile and can be replaced by ligands such as pseudohalides or monoanionic thiolates such as diphenyldithiophosphinate (Ph₂PS₂^?) or pyridine‐2‐thiolate (pyS^?). X‐ray structure analyses of [ReN(CN)(HL^Ph)(L^Ph)] and [ReN(pyS)(HL^Ph)(L^Ph)] show that the bonding situation of the NHC ligands (Re–C(carbene) distances between 2.086(3) and 2.130(3) Å) in the product is not significantly influenced by the ligand exchange. The potentially bidentate pyS^? ligand is solely coordinated via its thiolato functionality. Hydrogen atoms of each one of the phenyl rings come close to the unoccupied sixth coordination positions of the rhenium atoms in the solid state structures of all complexes. Re–H distances between 2.620 and 2.712Å do not allow to discuss bonding, but with respect to the strong trans labilising influence of “N^3?”, weak interactions are indicated.     

金属卟啉及其与咪唑络合物的电喷雾质谱研究

利用电喷雾电离质谱（ESI－MS）研究了3种金属卟啉化合物（MTPP＝MnTPP,TeTPP和CoTPP）,探讨了在这些化合物中苯取代基与卟啉环间的键合能力以及金属卟啉与咪唑的配位情况。研究结果表明,金属卟啉的外围取代基苯基与卟啉环的键合能力按Mn、Fe和Co的次序变弱。金属卟啉与咪唑形成的络合物的离子丰度随配体浓度的增加而增强;在相同的配体浓度下,络合物的离子丰度按Mn、Fe和Co顺序依次增加,其中,CoTPP络合物的稳定性最强。     

Complexes of cis -dihalogenorhenium(V) with iminophenol

Complexes cis-[ReOX₂(msa)(PPh₃)]?[X?=?Cl(1), I(2)] were prepared from trans-[ReOCl₃(PPh₃)₂] or trans-[ReOI₂(OEt)(PPh₃)²] with 2-(1-iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the bonding distances and angles in 1 and 2 are nearly identical, and that the two halides in each complex are coordinated cis to each other in the equatorial plane cis to the oxo group. Rhenium(V) complexes with cis diiodides are rare. All bonding distances and angles are in the expected ranges.     

Field Desorption Mass Spectrometry of Complex Anions Containing Rhenium and Technetium

Abstract

Field desorption mass spectra of Technetium and Rhenium anionic coordinate complexes have been obtained. lonization was principally by electron extraction from the anion, cation or neutral anion-cation pair, or by cation attachment to the intact molecule. The spectra were generally simple and allowed confirmation of known of proposed coordinate complex structures.     

Complexes of Oxorhenium(V) with Aromatic 2-Amino-Alcohols

Monooxo complexes of rhenium(V) with 2-aminophenol and some of its derivatives (H₂nod), containing the N,O donor-atom set, have been synthesized. Square-pyramidal complexes [ReO(nod)₂]^? were isolated by reaction with (n-Bu₄N) [ReOCl₄] in ethanol. In benzene the neutral species [ReOCL(Hnod)₂] were obtained. In the presence of hydrochloric acid in ethanol, the anionic complexes (n-Bu₄N) [ReOCl₃(Hnod)] were produced. Trans-[ReOCl₃(PPh₃)₂] was also reacted with some of the H₂nod ligands to yield [ReOCL₂(Hnod)(PPh₃]. The crystal structure of [ReOCl₂(Hmap)(PPh₃)] (H₂map = 2-aminobenzylalcohol) was determined; crystals are monoclinic, P2₁/n, with a = 15.065(6), b = 11.253(7), c = 15.850(7) Å, β = 94.27(4)°, U = 2680(2) &Aringsup3; and Z = 4. The structure was solved by the Patterson method and refined by full-matrix least-squares techniques to R = 0.042. The monoanionic Hmap^? ligand is coordinated as a bidentate through a neutral amino nitrogen and an anionic alcoholate oxygen atom, with the latter trans to the oxo group.     

Characterization of Rhodamine Self-Assembled Films Using Desorption Electrospray Ionization Mass Spectrometry

Growth process information and molecular structure identification are very important for characterization of self-assembled films. Here, we explore the possible application of desorption electrospray ionization mass spectrometry (DESI-MS) that provides the assembled information of rhodamine B (Rh B) and rhodamine 123 (Rh 123) films. With the help of lab-made DESI source, two characteristic ions [Rh B]⁺ and [Rh 123]⁺ are observed directly in the open environment. To evaluate the reliability of this technique, a comparative study of ultraviolet-visible (UV-vis) spectroscopy and our method is carried out, and the result shows good correlation. According to the signal intensity of characteristic ions, the layer-by-layer adsorption process of dyes can be monitored, and the thicknesses of multilayer films can also be comparatively determined. Combining the high sensitivity, selectivity, and speed of mass spectrometry, the selective adsorption of similar structure molecules under different pH is recognized easily from extracted ion chronograms. The variation trend of dyes signalling intensity with concentration of polyelectrolyte is studied as well, which reflects the effect of surface charge on dyes deposition. Additionally, the desorption area, surface morphology, and thicknesses of multilayer films are investigated using fluorescence microscope, scanning electron microscope (SEM), and atomic force microscopy (AFM), respectively. Because the desorption area was approximately as small as 2 mm², the distribution situation of organic dyes in an arbitrary position could be gained rapidly, which means DESI-MS has advantages on in situ analysis.

Characterization of Polylactides with Different Stereoregularity Using Electrospray Ionization Ion Mobility Mass Spectrometry

We investigated the effect of stereoregularity on the gas-phase conformations of linear and cyclic polylactides (PLA) using electrospray ionization ion mobility mass spectrometry (ESI-IM-MS) combined with molecular dynamics simulations. IM-MS analysis of PLA ions shows intriguing difference between the collision cross section (Ω_D) value of poly-L-lactide (PLLA) and poly-LD-lactide (PLDLA) ions with respect to their chain architecture and stereoregularity. In the singly sodiated linear PLA (l-PLA?Na⁺) case, both l-PLLA and l-PLDLA up to 11mer have very similar Ω_D values, but the Ω_D values of l-PLLA are greater than that of l-PLDLA ions for larger ions. In the case of cyclic PLA (c-PLA), c-PLLA?Na⁺ is more compact than c-PLDLA?Na⁺ for short PLA ions. However, c-PLLA exhibits larger Ω_D value than c-PLDLA for PLA ions longer than 13mer. The origin of difference in the Ω_D values was investigated using theoretical investigation of PLAs in the gas phase. The gas-phase conformation of PLA ions is influenced by Na⁺-oxygen coordination and the weak intramolecular hydrogen bond interaction, which are more effectively formed in more flexible chains. Therefore, the less flexible PLLA has a larger Ω_D value than PLDLA. However, for short c-PLA, concomitant maximization of both Na⁺-oxygen coordination and hydrogen bond interaction is difficult due to the constricted chain freedom, which makes the Ω_D value of PLAs in this range show a different trend compared with other PLA ions. Our study facilitates the understanding of correlation between stereoregularity of PLAs and their structure, providing potential utility of IM-MS to characterize stereoisomers of polymers. Figure

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芹菜素的电喷雾萃取电离串联质谱

采用实验室自制的电喷雾萃取电离源(EESI),结合串联质谱(MSn)技术,对芹菜素这一典型的黄酮类活性化合物的质谱行为进行了研究。实验表明,在正、负离子检测模式下,该化合物均能得到较好的EESI-MS信号,且在负离子检测模式下灵敏度更高。通过对比芹菜素的EESI-MS和电喷雾电离质谱(ESI-MS)谱图发现,芹菜素在EESI-MS和ESI-MS中的裂解规律相似,但是EESI是一种比ESI更软的电离模式。根据对芹菜素EESI-MS特征碎片离子的分析,提出了芹菜素在EESI-MS中裂解的基本规律,为EESI-MS技术用于分析、鉴定复杂基质中痕量芹菜素奠定了理论和实验基础。