Metallocenyl cations : I. Stable manganese-stabilised carbonium ions

Stable α-cymantrenylcarbonium ions have been identified by solution IR spectroscopy. The substitution of tert-phosphine for CO markedly stabilises the carbonium ions.     

Some considerations of the steady-state and transient behaviour of membrane-covered dissolved oxygen detectors

The behaviour of commercial, membrane-covered dissolved oxygen detectors is considerably more complicated than the orginal model of Mancy et al. would suggest. For example, the steady-state current is dependent both on the thickness and nature of the electrolyte behind the membrane. And transient currents obtained for switch-on of the detector are not completely described by the simple diffusional model. This paper examines these examples of more complicated behaviour. An analysis of the transient current for a step change in dissolved oxygen concentration is also given.     

Alkylation and silylation of directed enolates from diethylketene and organometallic reagents

Diethylketene and organometallic reagents form enolates capturable by methyl iodide or trimethylsilyl chloride with greater than 95% positional selectivity.     

The noncumulative effect of methyl substituents on the rate of addition of benzeneselenenyl chloride to olefins1

The rates and products of addition of benzeneselenenyl chloride to ethylene and its six Me substituted derivatives have been determined in methylene chloride at 25°. Unlike the addition of 4-chlorobenzenesulfenyl chloride to this same series of compounds, the effect of Me groups on the rates of addition is not cumulative. Also the regiochemistry of the product is different. For arenesulfenyl chloride additions, products of anti-Markownikoff orientation are formed preferentially under conditions of kinetic control. Under similar conditions regiospecific formation of the Markownikoff adduct is observed for the addition of benzeneselenenyl chloride to methylpropene and 2-methyl-2-butene. These data indicate a difference in both rate and product determining transition states between additions of arenesulfenyl and selenenyl chlorides to alkenes.     

The infrared spectrum of HC13F3

The infrared spectrum of HC¹³F₃ is reported for the first time. Fundamental frequency shifts due to carbon-13 substitution have been measured and rotational analyses of several of the fundamental and combination bands are given. Coriolis x-y and Fermi perturbations are evident in several of the bands. Table VI summarizes the data obtained in this study.     

Microwave spectrum,structure, and chemical bonding of trimethylbromosilane

The microwave spectrum of trimethylbromosilane (trimethylsilylbromide) has been investigated in the 26.5–40.0-GHz region. Spectra of several isotopic species have been observed, including the previously unreported spectrum of the ¹H¹²C³⁰Si⁸¹Br species, which yielded a B rotational constant of 1440.92 ± 0.02 MHz. From the experimental data it has been possible to derive the following structural parameters: SiBr = 2.235 ± 0.002 Å, SiC = 1.856 ± 0.010 Å, and ∠CSiBr = 107.5 ± 0.1°. The results have been compared to other relevant data and discussed in terms of prevailing chemical bonding principles.     

A new approach to helical primary structures of four-membered rings: (P)- and (M)-tetraspiro[3.0.0.0.3.2.2.2]hexadecane

A new approach to helical primary structures of four-membered rings uses a cycloaddition of a trimethylenketeniminium salt to suitable tailored methylenecyclobutanes to assemble the desired carbon framework. The results are short and effective syntheses of (M)-trispiro[3.0.0.3.2.2]tridecane [(M)-5], and (P)- and (M)-tetraspiro[3.0.0.0.3.2.2.2]hexadecane [(P)- and (M)-24]. Unlike helices of three-membered rings, the specific rotation decreases, as the length of the helix increases.     

西北太平洋部分海域AVHRR、TMI与MODIS遥感海表层温度的初步验证

选取[10～35°N,110～165°E]的西北太平洋海域,利用2002年7月～2005年12月Argo浮标数据对AVHRR/MODIS/TMI SST的daily（升轨）数据进行验证.结果表明：AVHRR/MODIS/TMI daily SST与Argo浮标5～6 m层温度总体的均方差rms在0.6～0.9℃,平均偏差bias在-0.2～0.2℃,平均绝对偏差bias_abs在0.3～0.7℃.这与三传感器全球范围的SST反演目标相当,说明在本区域SST反演不存在显著偏差.各遥感SST与浮标温度的差异存在季节变化,夏季偏高,很可能与夏季垂直混合较弱,比对采用的实测水温与海表温度差距较大有关.在3种遥感SST中,TMISST偏离实测值的程度最高,且偏离范围较大.作者认为这与该区域黑潮经过,产生诸多涡旋和锋面,SST时空变化剧烈而TMI空间分辨率较低有关.本研究将为此西北太平洋海域的多源SST融合提供一个比较可靠的依据.