Create plist file from string

I have this string:

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Secciones</key>
    <array>
        <dict>
            <key>Uid</key>
            <integer>1</integer>
            <key>DateInsert</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>DateModify</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>Name</key>
            <string>Seccion 1</string>
            <key>Description</key>
            <string>Esta es la sección 1.</string>
        </dict>
        <dict>
            <key>Uid</key>
            <integer>2</integer>
            <key>DateInsert</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>DateModify</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>Name</key>
            <string>Seccion 2</string>
            <key>Description</key>
            <string>Esta es la sección 2.</string>
        </dict>
        <dict>
            <key>Uid</key>
            <integer>3</integer>
            <key>DateInsert</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>DateModify</key>
            <date>3911-04-15T09:20:40Z</date>
            <key>Name</key>
            <string>Seccion 3</string>
            <key>Description</key>
            <string>Esta es la sección 3.</string>
        </dict>
    </array>
</dict>
</plist>

I want to create a plist file with this content. I have tried with this:

NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];

NSString *fileName = [documentsDirectory stringByAppendingPathComponent: @"开发者_高级运维sec.plist"];

NSLog(@"%@",documentsDirectory);
NSLog(@"%@",fileName);

//n is my string 
[n writeToFile:fileName 
    atomically:NO           
      encoding:NSStringEncodingConversionAllowLossy
         error:nil];

my console show:

2011-09-08 18:26:59.999 Catalogo-V1[1071:207] /Users/.../Library/Application Support/iPhone Simulator/4.3/Applications/6D96FC16-D6CB-4A03-A0F5-38A0C0C473C7/Documents

2011-09-08 18:27:00.000 Catalogo-V1[1071:207] /Users/.../Library/Application Support/iPhone Simulator/4.3/Applications/6D96FC16-D6CB-4A03-A0F5-38A0C0C473C7/Documents/sec.plist

But don´t create any file.

• Use the error parameter of writeToFile:atomically:encoding:error: method to retreive the error returned by the call, this will help debug

• Use NSUTF8StringEncoding instead of NSStringEncodingConversionAllowLossy (which is not eve an encoding!)

• Prefer using the NSPropertyListSerialization class to manipulate PLIST files serialization if possible.

• You may find useful to read the Property List Programming Guide too

NSStringEncodingConversionAllowLossy is not an encoding, use something like NSUTF8StringEncoding instead.